Isoform-specific immunolocalization of 14-3-3 proteins in atherosclerotic lesions of human carotid and main cerebral arteries

14-3-3 proteins are now recognized to have a wide range of potential functions and pathological relevance, such as regulating the intercellular signal processes of differentiation, the development and growth of cells, or preventing or mediating cell apoptosis and survival by controlling the localization of potential signaling molecules. We investigated the immunolocalization of 14-3-3 proteins in atherosclerotic lesions of human cerebral and carotid arteries using 14-3-3 isoform-specific antibodies to distinguish 7 isoforms, and confirmed the cell type localization using double immunofluorolabeling. 14-3-3 common (COM)-like immunoreactivity (IR) was intense, mainly in the foam cells and multinucleated giant cells of the carotid artery. The beta, gamma, epsilon, tau, eta, and zeta (6/7) isoform-specific antibodies showed similar results to those with anti-14-3-3 COM antibody. However, among these isoform-specific antibodies, the anti-eta isoform antibody most intensely immunolabeled multinucleated giant cells and foam cells, and the anti-zeta isoform antibody most intensely immunolabeled infiltrating vascular smooth muscle cells (VSMCs), in carotid plaques. Zeta IR was also observed in one part of the mural thrombus and in the nuclei of foam cells. Gamma isoform-like IR was relatively limited in cell components, but extracellular lesions were partly positive for this isoform. In the main cerebral arteries, the anti-epsilon isoform antibody most intensely immunolabeled infiltrating VSMCs in the intima of thickened fibrous cap plaques. Endothelial cells were also positive for the epsilon isoform. These findings may provide a basis for understanding the isoform-specific role associated with atherosclerotic lesions of the cerebral and carotid arteries.

Focal cerebral ischemia in the TNFalpha-transgenic rat

BACKGROUND

To determine if chronic elevation of the inflammatory cytokine, tumor necrosis factor-alpha (TNFalpha), will affect infarct volume or cortical perfusion after focal cerebral ischemia.

METHODS

Transgenic (TNFalpha-Tg) rats overexpressing the murine TNFalpha gene in brain were prepared by injection of mouse DNA into rat oocytes. Brain levels of TNFalpha mRNA and protein were measured and compared between TNFalpha-Tg and non-transgenic (non-Tg) littermates. Mean infarct volume was calculated 24 hours or 7 days after one hour of reversible middle cerebral artery occlusion (MCAO). Cortical perfusion was monitored by laser-Doppler flowmetry (LDF) during MCAO. Cortical vascular density was quantified by stereology. Post-ischemic cell death was assessed by immunohistochemistry and regional measurement of caspase-3 activity or DNA fragmentation. Unpaired t tests or analysis of variance with post hoc tests were used for comparison of group means.

RESULTS

In TNFalpha-Tg rat brain, the aggregate mouse and rat TNFalpha mRNA level was fourfold higher than in non-Tg littermates and the corresponding TNFalpha protein level was increased fivefold (p

CONCLUSION

Chronic elevation of TNFalpha protein in brain increases susceptibility to ischemic injury but has no effect on vascular density. TNFalpha-Tg animals are more susceptible to apoptotic cell death after MCAO than are non-Tg animals. We conclude that the TNFalpha-Tg rat is a valuable new tool for the study of cytokine-mediated ischemic brain injury.

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MESH Headings

• Animals
• Apoptosis/genetics
• Apoptosis/immunology
• Brain/immunology
• Brain/pathology
• Brain/physiopathology
• Brain Infarction/immunology
• Brain Infarction/pathology
• Brain Infarction/physiopathology
• Brain Ischemia/immunology
• Brain Ischemia/physiopathology
• Caspase 3/metabolism
• Cerebral Arteries/immunology
• Cerebral Arteries/pathology
• Cerebral Arteries/physiopathology
• Disease Models, Animal
• Encephalitis/immunology
• Encephalitis/pathology
• Encephalitis/physiopathology
• Female
• Infarction, Middle Cerebral Artery/immunology
• Infarction, Middle Cerebral Artery/physiopathology
• Male
• Microcirculation/genetics
• Microcirculation/immunology
• Neurons/immunology
• Neurons/pathology
• RNA, Messenger/metabolism
• Rats
• Rats, Sprague-Dawley
• Rats, Transgenic
• Regional Blood Flow/genetics
• Regional Blood Flow/immunology
• Tumor Necrosis Factor-alpha/genetics
• Tumor Necrosis Factor-alpha/immunology
• Up-Regulation/genetics
• Up-Regulation/immunology

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Grants

• R01 NS039588 NINDS NIH HHS
• R01 NS047395 NINDS NIH HHS

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Affiliation(s)

L Creed Pettigrew Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA Department of Neurology, University of Kentucky, Lexington, Kentucky, USA Veterans Administration (VA) Medical Center, Lexington, Kentucky, USA
Mark S Kindy Department of Neuroscience, Medical University of South Carolina, Charleston, South Carolina, USA Ralph H. Johnson VA Medical Center, Charleston, South Carolina, USA
Stephen Scheff Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, USA
Joe E Springer Department of Physical Medicine & Rehabilitation, University of Kentucky, Lexington, Kentucky, USA
Richard J Kryscio Department of Statistics and School of Public Health, University of Kentucky, Lexington, Kentucky, USA
Yizhao Li Jinan Great Wall Hospital, Jinan, Shandong, PR China
David S Grass Xenogen Biosciences, Cranbury, New Jersey, USA

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Targeting the tetraspanin CD81 blocks monocyte transmigration and ameliorates EAE

Leukocyte infiltration is a key step in the development of demyelinating lesions in multiple sclerosis (MS), and molecules mediating leukocyte-endothelial interactions represent prime candidates for the development of therapeutic strategies. Here we studied the effects of blocking the integrin-associated tetraspanin CD81 in in vitro and in vivo models for MS. In an in vitro setting mAb against CD81 significantly reduced monocyte transmigration across brain endothelial cell monolayers, both in rodent and human models. Interestingly, leukocyte as well as endothelial CD81 was involved in this inhibitory effect. To assess their therapeutic potential, CD81 mAb were administered to mice suffering from experimental autoimmune encephalomyelitis (EAE). We found that Eat2, but not 2F7 mAb directed against mouse CD81 significantly reduced the development of neurological symptoms of EAE when using a preventive approach. Concomitantly, Eat2 treated animals showed reduced inflammation in the spinal cord. We conclude that CD81 represents a potential therapeutic target to interfere with leukocyte infiltration and ameliorate inflammatory neurological damage in MS.

Brain endothelial PPARγ controls inflammation-induced CD4+ T cell adhesion and transmigration in vitro

An important step in the pathogenesis of multiple sclerosis is adhesion and transmigration of encephalitogenic T cells across brain endothelial cells (EC) which strongly relies on interaction with EC-expressed adhesion molecules. We provide molecular evidence that the transcription factor peroxisome proliferator-activated receptor gamma (PPARgamma) is a negative regulator of brain EC inflammation. The PPARgamma agonist pioglitazone reduces transendothelial migration of encephalitogenic T cells across TNFalpha-stimulated brain EC. This effect is clearly PPARgamma mediated, as lentiviral PPARgamma overexpression in brain EC results in selective abrogation of inflammation-induced ICAM-1 and VCAM-1 upregulation and subsequent adhesion and transmigration of T cells. We therefore propose that PPARgamma in brain EC may be exploited to target detrimental EC-T cell interactions under inflammatory conditions.

Tumor necrosis factor-alpha up-regulates glucuronosyltransferase gene expression in human brain endothelial cells and promotes T-cell adhesion

Stimulation of human brain microvascular endothelial cells (SV-HCECs) with tumor necrosis factor-alpha (TNF-alpha) up-regulates sulfoglucuronosyl paragloboside (SGPG) synthesis in a dose- and time-dependent manner. After TNF-alpha exposure at a concentration of 50 ng/ml for 24 hr, we observed a seven- to tenfold elevation of SGPG concentration. Interleukin-1beta (IL-1beta) at a concentration of 10 ng/ml and the combined doses of TNF-alpha and IL-1beta were less effective than TNF-alpha alone. TNF-alpha also stimulated T-cell (Jurkat) adhesion with SV-HCECs via SGPG-L-selectin recognition: this was determined by double-label immunofluorescent staining with SGPG and L-selectin antibodies. The number of T cells bound to SV-HCECs after different cytokine stimulations was proportional to the SGPG concentration, and the cell attachment was inhibited by anti-SGPG and anti-L-selectin antibodies, respectively. Our data unequivocally establish that inflammatory cytokines, particularly TNF-alpha, stimulate the glucuronosyltransferse, GlcAT-P, and GlcAT-S, gene expression in brain endothelial cells and promote T-cell adhesion via SGPG-L-selectin recognition, a preliminary step for onset of neuroinflammation.

The value of detecting anti-VZV IgG antibody in CSF to diagnose VZV vasculopathy

BACKGROUND

Factors that may obscure the diagnosis of varicella zoster virus (VZV) vasculopathy include the absence of rash before TIAs or stroke as well as similar clinical features and imaging, angiographic, and CSF abnormalities to those of other vasculopathies. Diagnosis relies on virologic confirmation that detects VZV DNA, anti-VZV IgG antibody, or both in the CSF.

METHODS

We reviewed our current 14 cases of patients diagnosed with VZV vasculopathy based on combined clinical, imaging, angiographic, or CSF abnormalities. All CSFs must have been tested for VZV DNA by PCR and for anti-VZV IgG antibody by enzyme immunoassay and found to be positive for either or both. Of the 14 subjects, 8 had a history of recent zoster, whereas 6 had no history of zoster rash before developing vasculopathy.

RESULTS

All 14 subjects (100%) had anti-VZV IgG antibody in their CSF, whereas only 4 (28%) had VZV DNA. The detection of anti-VZV IgG antibody in CSF was a more sensitive indicator of VZV vasculopathy than detection of VZV DNA (p < 0.001).

CONCLUSIONS

In varicella zoster virus (VZV) vasculopathy, the diagnostic value of detecting anti-VZV IgG antibody in CSF is greater than that of detecting VZV DNA. Although a positive PCR for VZV DNA in CSF is helpful, a negative PCR does not exclude the diagnosis of VZV vasculopathy. Only when the CSF is negative for both VZV DNA and anti-VZV IgG antibody can the diagnosis of VZV vasculopathy be excluded.

Why now? Moving from stroke risk factors to stroke triggers

PURPOSE OF REVIEW

While chronic risk factors for stroke are reasonably well understood, the acute precipitants, or triggers, of stroke, remain relatively understudied.

RECENT FINDINGS

Several converging lines of evidence indicate that transient perturbations in systemic metabolism may provoke the onset of cardiovascular events, including stroke. Epidemiologic data, including studies utilizing novel designs that consider intraindividual differences across different time periods, have been used to clarify triggers for myocardial ischemia, and these methods are beginning to be employed in stroke research. Acute infections, particularly upper respiratory infections, and other inflammatory stimuli have emerged as important triggers of acute ischemic stroke. The mechanisms involved include immunologically mediated activation of platelets and endothelial dysfunction. There also appears to be a period of time, or 'stroke-prone state', characterized by diffuse activation of the vasculature during which patients may be at increased risk of initial and recurrent ischemic events.

SUMMARY

Confirmation of these findings in further studies may help elucidate the mechanisms behind this short-term increase in stroke risk. Improved methods of assessment of this period of heightened susceptibility could lead to more temporally focused preventive interventions.

CD163 identifies perivascular macrophages in normal and viral encephalitic brains and potential precursors to perivascular macrophages in blood

Perivascular macrophages are uniquely situated at the intersection between the nervous and immune systems. Although combined myeloid marker detection differentiates perivascular from resident brain macrophages (parenchymal microglia), no single marker distinguishes perivascular macrophages in humans and mice. Here, we present the macrophage scavenger receptor CD163 as a marker for perivascular macrophages in humans, monkeys, and mice. CD163 was primarily confined to perivascular macrophages and populations of meningeal and choroid plexus macrophages in normal brains and in brains of humans and monkeys with human immunodeficiency virus or simian immunodeficiency virus (SIV) encephalitis. Scattered microglia in SIV encephalitis lesions and multinucleated giant cells were also CD163 positive. Consistent with prior findings that perivascular macrophages are primary targets of human immunodeficiency virus and SIV, all SIV-infected cells in the brain were CD163 positive. Using fluorescent dyes that definitively and selectively label perivascular macrophages in vivo, we confirmed that dye-labeled simian perivascular macrophages were CD163 positive and able to repopulate the central nervous system within 24 hours. Flow cytometric studies demonstrated a subset of monocytes (CD163(+)CD14(+)CD16(+)) that were immunophenotypically similar to brain perivascular macrophages. These findings recognize CD163(+) blood monocytes/macrophages as a source of brain perivascular macrophages and underscore the utility of this molecule in studying the biology of perivascular macrophages and their precursors in humans, monkeys, and mice.

Reduced ingestion of sweetened milk induced by interleukin-1 and lipopolysaccharide is associated with induction of cyclooxygenase-2 in brain endothelia

Previous studies have shown that interleukin-1 (IL-1) and lipopolysaccharide (LPS) administration to animals induces behavioral changes, including a reduction in feeding. These effects of IL-1 and LPS have been shown to be sensitive to inhibitors of cyclooxygenase (COX).

OBJECTIVES

To determine the relationships between induction of COX-2 in the brain with IL-1beta- and LPS-induced changes in body temperature, plasma corticosterone and feeding.

METHODS

Mice were injected with intraperitoneal doses of IL-1beta and LPS that decreased feeding. The induction of COX-2 was studied immunocytochemically in the brain, in parallel with core body temperature, the drinking of sweetened milk, and plasma concentrations of corticosterone.

RESULTS

COX-2 immunoreactivity (ir) was sparse in the brains of the untreated mice, but IL-1beta and LPS both increased its expression. This COX-2 induction appeared to be confined to blood vessels, and was not markedly region specific. Induction was evident 30 min after IL-1 or LPS, and was greater at 90 than at 30 min. COX-2-ir in the parenchyma did not change significantly. Thus induction of COX-2 occurred in brain endothelia in parallel with the reduction in feeding. This is consistent with the previously determined sensitivity of IL-1-induced changes in feeding to selective COX-2 inhibitors, and the responses to IL-1 in COX-2-deficient mice. The time courses of the IL-1- and LPS-induced increases in plasma corticosterone paralleled those in the reduction in milk drinking, however, the changes in body temperature appeared later.

CONCLUSIONS

Endothelial COX-2 may be involved in IL-1- and LPS-induced decreases in milk drinking, and possibly in the HPA axis activation. The decreased milk drinking may occur when IL-1 and LPS bind to receptors on brain endothelial cells subsequently inducing COX-2 and the production of prostanoids which elicit the reductions in milk drinking. Thus the behavioral effects of peripherally administered IL-1 and LPS appear to be mediated by multiple mechanisms, including endothelial COX-2, and vagal afferents.

Astrocytes and microglia differentially regulate trafficking of lymphocyte subsets across brain endothelial cells

Feline brain endothelial cells (BECs), astrocytes, and microglia were combined in different configurations in a cell culture insert system to assess the effect of different cell types on the trafficking of peripheral blood mononuclear cell (PBMC) subsets in response to feline immunodeficiency virus (FIV). The addition of astrocytes to BECs significantly increased the adherence of PBMCs. This increase in adherence was suppressed by microglia, whereas microglia alone had no effect on PBMC adherence. FIV exposure of the glial cells did not alter PBMC adherence as compared to same configurations with untreated cells. All PBMC subsets showed some level of trafficking across the endothelial cell layer. The level of trafficking of monocytes and B cells was significantly increased if astrocytes were present. The presence of microglia with the astrocytes reduced transmigration across all PBMC subsets. FIV exposure of astrocytes significantly increased the percentage of CD8 T cell transmigration from 24% to 64% of the total CD4 and CD8 numbers. The presence of microglia significantly reversed the preferential trafficking of CD8 cells in the presence of astrocytes. The results suggested that interaction between the triad of endothelial cells, astrocytes, and microglia played an important, but varying, role in the trafficking of different PBMC subsets. In general, astrocytes had a positive effect on trafficking of PBMCs, while microglia had a suppressive effect. Effects of FIV on trafficking were largely restricted to increases seen in CD8 T cells and monocytes.

Rosuvastatin, but not Simvastatin, Provides End-Organ Protection in Stroke-Prone Rats by Antiinflammatory Effects

OBJECTIVE

Brain abnormalities, preceded by a systemic inflammation, develop in spontaneously hypertensive stroke-prone rats (SHRSP). In this model, we investigated whether the hydrophilic statin, rosuvastatin, influences the development of inflammation associated with brain abnormalities. Because differences in hydrophilicity/hydrophobicity contribute to the differences in statin pharmacology, we also evaluated the effects of simvastatin, a lipophilic molecule

METHODS AND RESULTS

SHRSP, fed a high-salt diet, were treated long-term with vehicle or rosuvastatin (1 and 10 mg/kg per day). Brain abnormalities developed after 40+/-5 days and after 60+/-5 days of salt loading, in vehicle-treated and in rosuvastatin-treated (1 mg/kg per day) SHRSP, respectively. After 100 days of treatment, no damage was detectable in 30% of the rats treated with the highest dose of the drug. In comparison with vehicle-treated SHRSP, rosuvastatin treatment attenuated the transcription of monocyte chemoattractant protein-1, transforming growth factor-beta1, IL-1beta, and tumor necrosis factor-alpha in the kidney, and of P-selectin in brain vessels and increased the transcription of endothelial nitric oxide synthase mRNA in the aorta. Urinary excretion of acute-phase proteins increased with time in vehicle-treated animals but remained negligible in drug-treated animals. These effects are independent of changes in physiological parameters. Treatment of SHRSP with simvastatin (2 to 20 mg/kg per day) did not exert any protective effect.

CONCLUSIONS

Rosuvastatin attenuates inflammatory processes associated with cerebrovascular disease.

CD163-positive perivascular macrophages in the human CNS express molecules for antigen recognition and presentation

Perivascular macrophages (PVM) constitute a subpopulation of resident macrophages in the central nervous system (CNS) that by virtue of their strategic location at the blood-brain barrier potentially lend themselves to a variety of important functions in both health and disease. Functional evidence suggests that PVM play a supportive role during experimental autoimmune encephalomyelitis in rodents. However, the function of PVM in the human CNS remains poorly characterized. We first set out to investigate the validity of the antibody EDhu1, which recognizes human CD163, to specifically identify human PVM. Second, we wanted to gain insight into the function of PVM in antigen recognition and presentation and therefore we studied the expression of DC-SIGN, mannose receptor, MHC class II, and several costimulatory molecules by PVM in the normal and inflamed human CNS (multiple sclerosis (MS) brain lesions). Conventional immunohistochemistry and double-labeled immunofluorescence techniques were used. We show that CD163 specifically reveals PVM in the normal human CNS. In MS lesions, CD163 staining reveals expression on foamy macrophages and microglia, besides an upregulation of the amount of PVM stained. In contrast, mannose receptor expression is restricted to PVM in both normal and inflamed brain tissue. Furthermore, we show that a subpopulation of PVM in the human brain express several molecules involved in antigen recognition, presentation, and costimulation. Therefore PVM, which occupy a strategic location at the BBB, are equipped to recognize antigen and present it to T cells, supporting a role in the regulation of perivascular inflammation in the human CNS.

New models of intravital microscopy for analysis of chemokine receptor-mediated leukocyte vascular recognition

Chemokines control selective targeting of circulating leukocytes to the microvasculature by triggering inside-out signal transduction pathways leading to integrin-dependent adhesion. Presently, a few examples of presentation of chemokines by the inner surface of blood vessels responsible for triggering leukocyte arrest are available. A complete pattern of chemokine expression and presentation by the endothelium in different tissues and in homeostatic versus inflammatory conditions is still lacking. This review describes a novel intravital microscopy model allowing visualization of cerebral vessels through the skull, and analysis of the interactions between different leukocyte subpopulations and the endothelium in brain superficial microvasculature of mice. It has been recently shown that inflamed brain endothelium expresses a combination of adhesion ligands and activating factor(s) for G(i)-linked receptors that together mediate lymphocyte recruitment, and that the combination of molecules involved in this central nervous system (CNS) venule adhesion cascade strongly favors the arrest of activated versus nai;ve T cells. However, the identification of the chemokine(s) expressed by the endothelium leading to integrin activation and arrest still remains to be determined. The new approach presented here to study the brain microcirculation may provide an useful tool for further investigations of physiologic and pathologic events that occur in the CNS.

[Immunomorphological analysis of the vascular stroma in glioblastoma]

The aim of the study was to characterize vascular stroma in glioblastoma (GB), to analyze its immunomorphological features, and to seek a relationship between patients' age and characteristics of the tumor microcirculation. Subjects in the study were 38 patients with GB, divided into two groups according to their age: group I--14 patients aged under 49 (from 32 to 49), and group II--24 patients over 50 years of age (51-78). Main types of vessels were specified: microvessels with normal morphology (capillaries, arterioles/venules), telangiectases, haemangioma--like forms, and microvascular proliferation types--simple and glomeruloid. An immunohistochemical analysis of the vascular stroma was performed with monoclonal antibodies against vWf and CD31, ASM, and Collagen IV (DAKO) to visualize the vessel wall components. The immunomorphological analysis was carried out for particular types of vessels separately. The vWf and ASM expression ratios--percentage of immunopositive area on 10 representative tumor fields under 100 x HPF--were assessed using a computer image analyzer. The incidence of some vessel types was dependent on the patients' age: in group I vascular--rich areas were more numerous, while in group II glomeruloid proliferation was more frequent--20/24-83.3% vs 8/14-57.1%. Immunoreactivity of the examined antigens was not related to the patients' age. The endothelial markers positivity was found within cells directly around the vascular lumen, and the reaction with vWf was more pronounced than CD31 reactivity. The most intense reactions were noted in proliferative changes of both types and in capillaries. ASM reactivity was found in abluminal cells within all types of vessels, most abundant in glomeruloid proliferation. ASM positivity was present also in some capillaries. Collagen IV staining revealed various abnormalities in the vascular basement membrane structure. No significant intergroup differences were found in the vWf and ASM expression ratios. However, in both groups the ASM expression ratio was significantly higher than that of vWf expression (p < 0.001).

CONCLUSION

Expression of the vascular wall antigens under study depends on the blood vessel type. The number of cells with smooth muscle phenotype is significantly higher than that of endothelial cells, especially within proliferative vascular changes. Microvascular changes intensity is higher in the older patient group.

Focal encephalitis in the Lewis rat induced by intracerebral enterotoxin superantigen and amplified by activated intravenous splenocytes

The histological response after intracerebral (IC) injection of superantigen (SAg) was investigated in unprimed Lewis rats. The staphylococcal enterotoxins (SE) A (SEA), and E, but not B or saline, induced a variable perivascular inflammation in the injected hemisphere (6.7 +/- 6.1 cuffs per tissue section with SEA; mean +/- SD). Adoptive transfer of mitogen activated splenocytes (AS) augmented the response to SEA significantly (18.5 +/- 11.4; P<0.05). With or without AS transient bilateral perivascular cuffs were observed around the ventricles and in the corpus callosum up to 3 days after IC injection. The findings demonstrate that local expression of SAg in the brain can cause encephalitis, depending on the number of activated T cells in the circulation.

Frequency and patterns of subclinical cognitive impairment in patients with ANCA-associated small vessel vasculitides

We investigated the prevalence of disease-related cognitive impairment in patients with anti-neutrophil cytoplasmic antibodies (ANCA)-associated small vessel vasculitides (SVV). We studied 43 patients with ANCA-associated SVV (Wegener's granulomatosis (WG), Churg-Strauss syndrome (CSS) and microscopic polyangiitis (MP)), with no evidence of focal neurological deficits and dementia and in whom other potential causes of cognitive decline were carefully excluded. All patients underwent a detailed neuropsychological evaluation and their performances were compared with those of matched healthy controls. Patients were considered to be affected by subclinical cognitive impairment when they had abnormal results in at least two neuropsychological tests. Magnetic resonance imaging (MRI) scans of the brain were also obtained in 11 patients.The average neuropsychological test scores were not significantly different between the SVV patients and the control subjects. Thirteen patients had abnormal results in two tests (seven patients) or three or more tests (six patients). Most frequently, abnormal tests were the Rey Figure Recall (six cases), the Wisconsin Card Sorting Test (six cases), and the reaction times (eight cases). The frequency and extent of brain MRI abnormalities were higher in impaired than in unimpaired patients. This study demonstrates that 30% of clinically nondemented SVV patients can have a subclinical neuropsychological impairment, characterized by mild abstract reasoning loss, mental speed reduction and nonverbal memory impairment. MRI findings in impaired patients are consistent with the presence of an SVV-mediated subcortical damage of the brain.

Chromatin image analysis provides new evidence of the relation of lymphocytes to cytokines and sCAM in the inflammatory nature of atherosclerosis

Comparative analysis of cytokines and sCAM secretion within the lymphocyte chromatin state are possible evidence of inflammatory reactions in atherosclerosis. Two types of response were studied: coagulation and fibrinolysis (incubation of blood clot within 6 hours at 37 degrees C) and standardized viscosimetric flow using a rotational viscometer (shear rate 100 l/s, 60 seconds at 37 degrees C, and incubation within 6 hours at 37 degrees C). Cytokines IL-1alpha, IL-1beta, IL-6, IL-8, IL-10 (Immunotech, France), endothelin-1, and soluble cell adhesion molecules (sCAM) sP- and sE-selectin, sICAM-1, and sVCAM-1 (R&D, UK) have been determined using ELISA kits (photometer, Biomek-1000, Beckman, USA). The chromatin of lymphocyte nuclei was studied using the computer TV morphodensitometry system DiaMorph (Russia) and smears dyed specifically for DNA. Correlational changes in morphodensitometric (MDM) parameters and cytokine and sCAM levels in two tests were compared to initial levels. After rheologic testing, lymphocyte nuclei as a whole had not changed, but chromatin activity had decreased. Reorganization of nuclei after the coagulation test was observed. Endothelin-1 and sP- and sE-selectin levels were not related to function of lymphocytes (by MDM data) as seen in both tests; it is probable that another cell-cell communication mechanism had been switched on. We established a strong correlation between chromatin activity of lymphocytes and the serum concentration of IL-1beta, IL-6, and IL-10, which are the active participants in the pro- and anti-inflammatory program in atherogenesis. Results are evidence of the role of lymphocytes in pro- and anti-inflammatory cytokine reactions and cytokine-like sCAM activity in atherosclerosis.

Expression of interleukin-1 beta in lipopolysaccharide stimulated monocytes derived from patients with aneurysmal subarachnoid hemorrhage is correlated with cerebral vasospasm

Cerebral arterial vasospasm is a frequent complication after aneurysmal subarachnoid hemorrhage (SAH). Immunological activation may affect the development of vasospasm. This study measured the cytokines released from lipopolysaccharide-stimulated monocytes of SAH patients. We measured cerebral artery diameters before and after surgery for SAH. The activation index of interleukin-1 beta (IL-1 beta), but not tumor necrosis factor-alpha (TNF-alpha), was higher in patients with symptomatic vasospasm (5.6+/-1.7; n=11) than in patients without (1.8+/-0.4; n=11) (P=0.039). Furthermore, the IL-1 beta activation index was correlated with the degree of the postoperative angiographic vasospasm (correlation coefficient=-0.66, P=0.007). Individual variation in systemic immune activation, measured by monocyte-derived IL-1 beta expression levels after stimulation, may be associated with the development of vasospasm after aneurysmal SAH.

Isolated angiitis of the central nervous system: lack of inflammation after long-term treatment

A case of isolated angiitis of the CNS was observed for 5 years. Initial response to cyclophosphamide was followed by relapse on therapy interruption. After renewed treatment, clinical stabilization was achieved despite progressive stenoses shown by angiography. The patient died of cyclophosphamide-induced myelodysplastic syndrome. Autopsy revealed lack of inflammation, vascular scarring, and amyloid angiopathy. We conclude that cure from isolated angiitis of the CNS is possible and that the risk of overtreatment should be minimized.

Interleukin-6 and development of vasospasm after subarachnoid haemorrhage

The authors characterized the role of interleukins in the cerebrospinal fluid (CSF) in the development of vasospasm after subarachnoid haemorrhage (SAH), particularly interleukin-6 (IL-6). Concentrations of interleukin-1 beta (IL-1 beta), IL-6, and interleukin-8 (IL-8) were measured serially in CSF of 24 patients and in serum of 9 patients with SAH and correlated clinically. Additionally, the effects of the same cytokines on the cerebral arteries of dogs were analyzed on angiograms after intracisternal injection. Changes in levels of eicosanoids, angiogenic factors, and soluble cell adhesion molecules were investigated in the CSF of injected dogs. CSF concentrations of IL-6 and IL-8 were elevated significantly above control levels from the acute stage of SAH until the chronic stage. Patients with symptomatic vasospasm had significantly higher levels of IL-6 as well as IL-8 in CSF on days 5 and 7. Intracisternal injection of IL-6 induced long-lasting vasoconstriction in five out of eight dogs, while IL-8 did not. The diameter of canine basilar artery after IL-6 was reduced 29 +/- 5% from pretreatment diameter at 8 hours. Prostaglandins E2 and I2 were elevated in CSF for the first 4.5 hour of this IL-6-induced vasospasm. Neither angiogenic factors such as platelet-derived growth factor-AB and vascular endothelial growth factor nor soluble cell adhesion molecules were significantly elevated in CSF. IL-6, which increases to very high concentrations in CSF after SAH, may be important in inducing vasospasm, as IL-6 produced long-lasting vasoconstriction in the canine cerebral artery, which may be partly related to activation of the prostaglandin cascade.

Chemotactic activity and IL-8 levels in the cerebrospinal fluid in canine steroid responsive meningitis-arteriitis

Steroid responsive meningitis-arteriitis (SRMA) is a systemic immune disorder, characterized by inflammatory-stenosing lesions of the meningeal arteries and meningitis. The predilection of the disease for the central nervous system (CNS) remains unexplained. In this study, chemotactic activity and chemotactic factors were measured in the cerebrospinal fluid (CSF) of dogs with SRMA. CSF of dogs with SRMA exerted a marked chemotactic activity for leukocytes. Neutrophils were attracted to a similar degree as by CSF from animals with bacterial encephalitis. Chemotactic activity was also noted for mononuclear cells, however, by far weaker than in CSF from animals with viral encephalitis. While the inflammatory process could be suppressed with glucocorticoid treatment, the chemotactic activity of CSF persisted. We could identify IL-8-like activities using a desensitization assay in the CSF of animals with SRMA and also found increased IgA levels. Increased chemotactic activity for polymorphonuclear leukocytes correlated positively with the levels of IL-8-like activity in CSF. Our observations clearly suggest that in SRMA chemotactic factors are generated in the CNS. These include IL-8, but probably also others. The intensity of this production appears to correlate with IgA levels in the CSF suggesting either a causal link or reflecting the severity of the inflammation.

Anticardiolipin antibody aggravates cerebral vasospasm after subarachnoid hemorrhage in rabbits

BACKGROUND AND PURPOSE

We previously reported that patients with antiphospholipid antibodies (aPLs) frequently demonstrate cerebral infarction due to cerebral vasospasm after subarachnoid hemorrhage (SAH). To examine the participation of aPLs in the pathogenesis of vasospasm after SAH, we studied the relationships of aPLs and SAH in an animal model.

METHODS

SAH was produced in 34 rabbits that received two subarachnoid injections of autologous arterial blood. The animals were divided into four experimental groups: SAH was induced in group A (n=9), intracutaneous injection of cardiolipin (CL) was performed before the induction of SAH in group B (n=5), intravenous injection of CL was performed before SAH in group C (n=12), and cyclosporin A was infused intravenously after the intravenous injection of CL and induction of SAH in group D (n=8). Enzyme-linked immunosorbent assay identifying the titer of IgG CL antibodies, neurological evaluation, cerebral angiography, and histological examination were performed in all four groups.

RESULTS

A significant elevation of anti-CL antibodies, aggravation of neurological deficit, and reduction of caliber of the basilar artery were observed in rabbits that received the intravenous immunization of CL (group C). The administration of cyclosporin A reduced the titer of anti-CL antibody, aggravation of neurological deficit, constriction of basilar artery, and the incidence of cerebral infarction (group D).

CONCLUSIONS

Anti-CL antibodies may therefore be involved in the deterioration of cerebral vasospasm after SAH.

Clinicopathological and genetic studies of two further Italian families with cerebral autosomal dominant arteriopathy

We report on two Italian families with an early-adult onset autosomal dominant disorder, characterized by leukoencephalopathy, migraine, psychiatric disturbances, stroke and dementia. These findings fulfill the diagnostic criteria for cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) syndrome. Moreover, to confirm the CADASIL gene location to 19p12, we performed a linkage analysis with four microsatellite markers. The results of the genetic study gave positive but not significant lod scores, indicating only weak evidence of a linkage with 19p12. In one autopsy case, we found extensive ischemic changes due to the selective involvement of the small muscular arteries of the cerebral white matter. The lesions consisted of a thickening of the media with deposition of granular eosinophilic material. Ultrastructural examination of the arterial walls showed graded damage to smooth muscle cells, mostly of the longitudinal layer, and an abnormal proliferation of basal lamina components. Immunocytochemical analysis showed strong reactivity using antibodies to collagen IV and smooth myosin proteins. The results suggest a primary involvement of the smooth muscle cells of small cerebral arteries, with a secondary alteration of basal lamina components and elastic tissue.

Expression of intercellular adhesion molecule 1 (ICAM-1) on the cerebral artery following subarachnoid haemorrhage in rats

In order to study how immune-inflammatory responses are involved in the pathogenesis of cerebral vasospasm after subarachnoid haemorrhage (SAH), the kinetics of expression of the intercellular adhesion molecule 1 (ICAM-1), a ligand for the leucocyte adhesion receptor, were studied on the cerebral arteries following SAH in rats. The SAH was induced by intracisternal injection of arterial blood. The rats were sacrificed at specified times: immediately after induction of SAH to seven days after SAH. Cryostat sections of the basilar artery (BA) were prepared and incubated with anti-rat ICAM-1 antibody. Morphometric analysis of the BA revealed a significant narrowing of the luminal diameter on Day 2 following SAH. While in the non-treated normal animals, no nor only weak expression of ICAM-1 was observed on the endothelial layer of the BA, there was greater expression of ICAM-1 on the endothelial layer of the BA in SAH rats, and the expression was observed also in the medial layer of the artery from Day 2 to Day 5 following SAH. The present results indicate that SAH really causes responses in the cellular immunity not only in the endothelial layer, but also in the medial layer of the artery as a target of immune damage, which is presumed to be one of the important steps in the development of cerebral vasospasm.

Differential degeneration of the cerebral microvasculature in Alzheimer's disease

We used immunocytochemical methods to define abnormalities in the cerebral endothelium and the vascular basement membrane in patients with Alzheimer's disease (AD) and in aging control subjects. Double immunostaining with antibodies to the endothelial cell markers CD34 and CD31 revealed an absence of endothelial staining in many capillary profiles that still appeared to retain their basement membranes stained by antibodies to collagen IV. Such differential labeling, clearly suggesting capillaries with collapsed or degenerated endothelium, was frequently (> 90% of cases) evident in AD but relatively lacking in brain regions or other diseases and controls (< 30%) free of amyloid beta (A beta) deposits. We suggest that this profound vascular phenomenon is concomitant with A beta deposition and implies abnormalities in the integrity of brain microvasculature related to neuronal degeneration in AD.

Attempts to induce immune-mediated cerebral arterial injury for an experimental model of moyamoya disease

To examine the possible role of immune complex-mediated reactions in moyamoya disease, a novel experimental system using a serum sickness vasculitis model combined with intracisternal administration of antibodies or antigens was developed. Twenty-eight male Japanese white rabbits were divided into four experimental groups. Group I was treated twice with intravenous injections of heterologous serum. In group II, intracisternal administration of antibodies or antigens was combined with the second injection of serum. Group III received a single intravenous injection of antigens simultaneously with intracisternal administration of antibodies. Group IV was a technical control group. Cerebral arteritis, although likely in the initial process, was induced only in groups II and III. This study suggests that the cerebral arteries rarely develop arteritis in a serum sickness model alone. The cerebral arteries may require additional intracisternal administration of antibodies or antigens to induce in situ deposition of immune complexes around them.

Expression of intercellular adhesion molecule 1 (ICAM-1) in Alzheimer's disease

In this study, 13 clinically and pathologically diagnosed cases of Alzheimer's disease were analyzed for the presence of intercellular adhesion molecule 1 (ICAM-1), ICAM-2, lymphocyte function associated antigen-1 (LFA-1), HLA-DR, LN-1, and LN-2. ICAM-1 was observed primarily on neuritic plaques and cerebrovascular endothelium. ICAM-1 was also shown to be present in brain tissue derived from 14 normal cases; however, the degree of immunoreactivity was quantitatively less compared to Alzheimer cases and was largely restricted to cerebrovascular endothelium. LFA-1 was shown to be present on microglial cells and leukocytes. Consistent with the findings of previous reports, HLA-DR was found to be expressed on microglial cells. In this study we failed to demonstrate dual immunolocalization for ICAM-1 and LFA-1, ICAM-1 and HLA-DR, or ICAM-1 and LN-2. As microglial cells express both HLA-DR and LFA-1, they may serve to mediate antigen presentation functions by interacting with lymphocyte ICAM-1. Alternately, the expression of these immune-associated glycoproteins on glial cells may be epiphenomenal occurring secondary to some aspect of the disease process. Finally, the presence of ICAM-1 within neuritic plaques raises the question as to whether adhesion may play some role in the process of neurite outgrowth and neurodegeneration.

The correlation between immunological reaction in the arterial wall and the time course of the development of cerebral vasospasm in a primate model

To investigate the role of immunological reactions in the development of cerebral vasospasm after subarachnoid hemorrhage (SAH), the authors studied the correlation between immune/inflammatory reactions in the arterial wall and the time course of vasospasm in primates. Twenty monkeys were divided into four groups of 5 animals each: 1) a control group of sham-operated animals, 2) animals subjected to angiography 3 days after the induction of SAH (3-day SAH), 3) animals subjected to angiography 7 days after SAH (1-week SAH), and 4) animals subjected to angiography 7 and 14 days after SAH (2-week SAH). To induce SAH, the main cerebral arteries on the right were dissected free of the arachnoid, and an autologous blood clot was placed around the arteries. To evaluate vasospasm, all animals underwent a baseline angiogram before SAH; angiography was repeated at different intervals in each group, as outlined above. Histopathological changes and the deposition of the immunoglobulin IgG in the arterial wall were evaluated immunohistochemically in each group. The cerebral arteries on the side of the clot showed evidence of mild vasospasm (-24.6% reduction) on the angiogram performed on Day 3, severe vasospasm (-51.7%) on Day 7, and mild vasospasm (-12.8%) on Day 14. The infiltration of inflammatory cells was most marked in the spastic arterial wall in the 1-week SAH group. In the 2-week SAH group, severe myonecrosis and intimal disruption were observed, even in the vessels that showed only mild vasospasm, and the inflammatory reactions had almost abated.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral arteriovenous malformations. A detailed morphological and immunohistochemical study using actin

Vascular musculature was studied in cerebral arteriovenous malformations using a monoclonal antibody against the muscle protein actin in 20 cases. The more typical vessels (arterial and venous types) and a number of abnormalities of the muscular layer were identified. The latter included (1) partially developed media; (2) two layers of the media separated by a well-formed internal elastic membrane; (3) total or partial disarray of the muscle coat; and (4) partial absence of the media. Previously described large capillaries proved to be postcapillary venules by virtue of having a distinct muscular layer. Serial sectioning indicated that the previously described "polypoid projections" of the media are mostly artifacts and the concept of "arterialization of veins in arteriovenous malformations" could not be substantiated. The actin method proved to be a useful adjunct to the conventional stains for accurate and selective detection of smooth-muscle cells.

Changes of neuropeptide immunoreactivity in cerebrovascular nerve fibers after experimentally produced SAH. Immunohistochemical study in the dog

The immunoreactivity of vasoactive intestinal polypeptide (VIP)-, substance P (SP)-, and neuropeptide Y (NPY)-containing nerve fibers in the basilar artery (BA) and proximal portion of the middle cerebral artery (M1) was immunohistochemically examined in the dog after experimentally produced subarachnoid hemorrhage (SAH). The SAH was produced by a single injection of fresh autologous arterial blood (1 ml/kg body weight) into the cisterna magna. The density (the averaged number of nerve fibers in a unit area) of VIP-, SP-, and NPY-immunoreactive perivascular nerve fibers in the M1 segment and the BA was markedly decreased (5% to 40% of the normal value) immediately after the injection. The density of VIP- and SP-immunoreactive perivascular fibers increased 2 or 3 weeks after SAH and became normal by the 63rd day after injection. On the other hand, no substantial recovery was observed in the density of NPY-immunoreactive perivascular fibers by 63 days after injection.

Distribution of anti-HRP antibodies in the central nervous system of immunized rats after disruption of the blood brain barrier

Lewis rats were immunized with horseradish peroxidase (HRP) injected intradermally in the hind foot pads; anti-HRP antibodies in the cerebrum were detected with a cytochemical reaction for HRP in sections incubated with the antigen (HRP), or after intravenous injection of HRP a few minutes before sacrifice. In two groups of animals the blood brain barrier was disrupted by a heat lesion or by a traumatic lesion (insertion of a canula into the lateral ventricle). In animals with a heat or with a traumatic lesion, anti-HRP antibody was detected not only in the vicinity of the lesion but also within the entire cerebral parenchyma and the choroid plexus. By electron microscopy, anti-HRP antibody was seen on the plasma membranes of endothelial cells and pericytes of the capillaries of the brain parenchyma and of the choroid plexus, and on the plasma membranes of the choroid plexus epithelium. Anti-HRP antibody was not seen in a group of immunized animals with an intact blood brain barrier or in a group of animals immunized 30 or more days after the brain lesion. These experiments have shown that significant levels of circulating antibody against an antigen (HRP), which is irrelevant to brain antigens, has access to and achieves a widespread distribution into the brains of animals with a disrupted blood brain barrier.

Identification of components of immunoglobulins in senile plaques by means of fluorescent antibody technique

Using a fluorescent antibody technique, sections of the brains of patients with senile dementia or Alzheimer's disease containing senile plaques were treated with rabbit antihuman immunoglobulins labelled with FITC (fluorescein isothiocyanate, BBL). The senile plaques and the cerebral amyloid angiopathy (drusige Entartung, Scholz, 1938) in the brains of patients with senile dementia or Alzheimer's disease showed specific fluorescence. Control sections from the brains of a girl who died from carcinoma of the stomach and of a female schizophrenic who died from lung abscess, showed only slight fluorescence in a few vessel walls. The presence of components or fragments of immunoglobulins in a senile plaques may mean that immunological factors are involved in their pathogenesis and probably also in that of senile dementia and Alzheimer's disease.

Tropism of Mycoplasma gallisepticum for arterial walls

The fatal encephalopathy associated with M. gallisepticum strain S6 in turkey poults was completely curable by treatment with tylosin or pleuromutilin. The lesions of cerebral polyarteritis disappeared after therapy. Polyarthritis developed in some birds after recovery from encephalitis. Immunofluorescent studies revealed that intravenously injected organisms became localized as microcolonies within the walls of cerebral and periarticular arteries, and in the glomeruli. Turkey IgG deposition was demonstrated on the glomerular basement membranes, but not in the arterial lesions. The results suggest that the pathologic changes caused by this microorganism are due to selective localization and growth in arteries.