Upregulation of vascular growth factors in multiple sclerosis: Correlation with MRI findings

Increased blood vessel density and endothelial cell proliferation in multiple sclerosis cerebral white matter

Multiple sclerosis (MS) is primarily considered an inflammatory demyelinating disease, however the role of vasculature in MS pathogenesis is now receiving much interest. MS lesions often develop along blood vessels and alterations in blood brain barrier structure and function, with associated changes in the basement membrane, are pathological features. Nevertheless, the possibility of angiogenesis occurring in MS has received little attention. In this study we used triple label enzyme immunohistochemistry to investigate blood vessel density and endothelial cell proliferation in MS samples (n=39) compared with control tissue to explore evidence of angiogenesis in MS. The results showed that in all MS samples examined blood vessel density increased compared with controls. The greatest increase was found in subacute lesions where numbers of positively stained vessels increased from 43.9+/-8.5% in controls to 84.2+/-13.3% (P=0.001). Furthermore, using an antibody against endoglin (CD105), a specific marker of proliferating endothelial cells, which are characteristic of angiogenesis, we have shown that vessels containing proliferating endothelial cells were more pronounced in all MS tissue examined (normal-appearing white matter, acute, subacute and chronic lesions, P>or=0.027) compared with control and this was greatest in the MS normal-appearing white matter (68.8+/-19.8% versus 10.58+/-6.4%, P=0.003). These findings suggest that angiogenesis may play a role in lesion progression, failure of repair and scar formation.

CD8 T cell-initiated vascular endothelial growth factor expression promotes central nervous system vascular permeability under neuroinflammatory conditions

Dysregulation of the blood-brain barrier (BBB) is a hallmark feature of numerous neurologic disorders as diverse as multiple sclerosis, stroke, epilepsy, viral hemorrhagic fevers, cerebral malaria, and acute hemorrhagic leukoencephalitis. CD8 T cells are one immune cell type that have been implicated in promoting vascular permeability in these conditions. Our laboratory has created a murine model of CD8 T cell-mediated CNS vascular permeability using a variation of the Theiler's murine encephalomyelitis virus system traditionally used to study multiple sclerosis. Previously, we demonstrated that CD8 T cells have the capacity to initiate astrocyte activation, cerebral endothelial cell tight junction protein alterations and CNS vascular permeability through a perforin-dependent process. To address the downstream mechanism by which CD8 T cells promote BBB dysregulation, in this study, we assess the role of vascular endothelial growth factor (VEGF) expression in this model. We demonstrate that neuronal expression of VEGF is significantly upregulated prior to, and coinciding with, CNS vascular permeability. Phosphorylation of fetal liver kinase-1 is significantly increased early in this process indicating activation of this receptor. Specific inhibition of neuropilin-1 significantly reduced CNS vascular permeability and fetal liver kinase-1 activation, and preserved levels of the cerebral endothelial cell tight junction protein occludin. Our data demonstrate that CD8 T cells initiate neuronal expression of VEGF in the CNS under neuroinflammatory conditions, and that VEGF may be a viable therapeutic target in neurologic disease characterized by inflammation-induced BBB disruption.

Relationship between Barkhof criteria and the clinical features of multiple sclerosis in northern Japan

We previously reported that the prevalence of multiple sclerosis (MS) in the Tokachi Province of Hokkaido increased from 8.6 to 13.1 per 100,000 individuals between 2001 and 2006. Here, we study the frequency of MS patients who fulfill the Barkhof criteria and identified their common features. All 47 subjects in our previous study, who fulfilled Poser's criteria, were included in this study. Of these, 33 satisfied the Barkhof criteria. In 2006, 9.2 per 100,000 MS patients fulfilled the Barkhof criteria; the percentage of patients who fulfilled these criteria was significantly higher among patients born after 1960 than among those born before 1960 (84.3% and 40.0%, respectively). The proportion of patients with conventional MS (C-MS) who fulfilled the Barkhof criteria was higher than that of patients with opticospinal MS (OS-MS) who fulfilled these criteria (93.9% and 71.4%, respectively). Longitudinally extensive spinal cord lesions (LESCLs) were not associated with the brain lesions defined in the Barkhof criteria (Barkhof brain lesions). In Tokachi Province, the increased percentage of MS patients who fulfill the Barkhof criteria was associated with increased C-MS incidence and an increase in the proportion of C-MS patients with Barkhof brain lesions among people born after 1960.

Role and therapeutic potential of VEGF in the nervous system

The development of the nervous and vascular systems constitutes primary events in the evolution of the animal kingdom; the former provides electrical stimuli and coordination, while the latter supplies oxygen and nutrients. Both systems have more in common than originally anticipated. Perhaps the most striking observation is that angiogenic factors, when deregulated, contribute to various neurological disorders, such as neurodegeneration, and might be useful for the treatment of some of these pathologies. The prototypic example of this cross-talk between nerves and vessels is the vascular endothelial growth factor or VEGF. Although originally described as a key angiogenic factor, it is now well established that VEGF also plays a crucial role in the nervous system. We describe the molecular properties of VEGF and its receptors and review the current knowledge of its different functions and therapeutic potential in the nervous system during development, health, disease and in medicine.

Aquaporin-4 autoimmune syndrome and anti-aquaporin-4 antibody-negative opticospinal multiple sclerosis in Japanese

Background

Antibodies to aquaporin-4 (AQP4) are found in a fraction of Japanese opticospinal multiple sclerosis (OSMS) patients. However, it remains unknown whether anti-AQP4 antibody-positive and negative OSMS patients possess an identical disease.

Objective

The objective of the current study was to clarify immunological differences between the two groups of patients.

Methods

We studied the serum antibody titers against AQP4 in 191 patients with idiopathic central nervous system demyelinating diseases and clarified their relationships with immunological parameters.

Results

Anti-AQP4 antibody positivity rate was higher in patients with OSMS (21/58, 36.2%), idiopathic recurrent myelitis (4/17, 23.5%), and recurrent optic neuritis (7/26, 26.9%), than in conventional MS (CMS) patients (6/90, 6.7%) and patients with other diseases (0/87). Anti-AQP4 antibody titer was significantly higher in patients with SS-A/B antibodies than in those without them. Anti-AQP4 antibody-negative OSMS patients showed significantly higher CD4+IFN-γ+IL-4−T cell percentages and intracellular IFN-γ/IL-4 ratios than anti-AQP4 antibody-positive patients, anti-AQP4 antibody-negative CMS patients, and healthy controls, and CD4+IFN-γ+IL-4−T cell percentages were negatively correlated with anti-AQP4 antibody titers.

Conclusion

Anti-AQP4 antibody-positive patients are immunologically distinct from anti-AQP4 antibody-negative OSMS patients owing to a Th2 shift in the former group in comparison to a Th1 shift in the latter.

Correlation between Magnetic Resonance Imaging Findings and Pathological Observations in Tumefactive Multiple Sclerosis

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system. Tumefactive MS (TMS) is a subtype of MS characterized by solitary or multiple mass lesions with open-ring enhancement on brain magnetic resonance imaging (MRI). Three TMS cases, diagnosed histopathologically by brain biopsy, that were difficult to distinguish from brain tumors or brain abscesses on MRI are presented. On T2-weighted imaging (T2WI) the lesions were high intensity in the center and periphery, with open-ring contrast enhancement at the periphery; iso- to low intensity areas (“T2 low rim”) were seen in the surrounding region. Histopathological examination revealed the characteristic features of TMS: severe central demyelination and focal necrosis, peripheral neovascularization and perivascular inflammatory cell infiltration, and perifocal edema. On immunochemistry, both the endothelial cells of the neovasculature and the surrounding macrophages in the periphery expressed vascular endothelial growth factor and monocyte chemoattractant protein-1, which mediate inflammation and angioneogenesis and increase vascular permeability. These findings correspond to the T2 low rim co-localizing with the site of gadolinium enhancement on MRI. Thus, the present study clearly demonstrates the correlation between the radiological features and the pathophysiological aspects of TMS, which may contribute to more precise diagnosis of TMS.

Multimodality-evoked potential study of anti-aquaporin-4 antibody-positive and -negative multiple sclerosis patients

Neuromyelitis optica (NMO) is claimed to be a distinct disease entity from multiple sclerosis (MS) because of its strong association with NMO-IgG/anti-AQP4 antibody; however, the in vivo role of the antibody remains unknown. Therefore, we aimed to clarify whether the presence of anti-AQP4 antibody is associated with any abnormalities in multimodality-evoked potentials in 111 patients with relapsing-remitting or relapsing-progressive MS, including the opticospinal form of MS, 18 of whom were seropositive for anti-AQP4 antibody. More patients with anti-AQP4 antibody showed a lack of the P100 component on visual-evoked potentials (VEPs) than those without the antibody (11/17, 64.7% vs. 20/84, 23.8%, p=0.003), whereas the frequency of delayed P100 latency was significantly higher in the latter group than in the former (1/17, 5.9% vs. 28/84, 33.3%, p=0.021). The frequencies of non-responses and delayed central sensory conduction times in median and posterior tibial nerve somatosensory-evoked potentials (SEPs) were not significantly different between anti-AQP4 antibody-positive and -negative patients. In terms of upper and lower limb motor-evoked potentials (MEPs), the frequencies of non-responses and delayed central motor conduction times did not differ significantly based on the presence or absence of anti-AQP4 antibody. The frequency of optic nerve lesions on MRI was significantly higher in anti-AQP4 antibody-positive patients than in anti-AQP4 antibody-negative patients (p=0.0137). Multiple logistic analyses revealed that anti-AQP4 antibody positivity (OR=8.406, p=0.02) and unevoked VEP responses (OR=35.432, p<0.001) were significantly related to development of severe visual impairment. Such an association of anti-AQP4 antibody with disability was not found for either severe motor or sensory impairment. These findings suggest a distinctive nature of optic nerve lesions between anti-AQP4 antibody-positive and -negative patients; lesions are supposed to be more necrotic in the former group and more demyelinating in the latter.

White matter hemodynamic abnormalities precede sub-cortical gray matter changes in multiple sclerosis

BACKGROUND

Hypoperfusion has been reported in lesions, normal-appearing white (NAWM) and gray matter (NAGM) of patients with clinically definite multiple sclerosis (MS) by using perfusion MRI. However, it is still unknown how early such changes in perfusion occur. The aim of our study was to assess the presence of hemodynamic changes in the NAWM and subcortical NAGM of patients with clinically isolated syndrome (CIS) in comparison to healthy controls and to patients with early relapsing-remitting (RR) MS.

METHODS

Absolute cerebral blood flow (CBF), blood volume (CBV) and mean transit time (MTT) were measured in the periventricular and frontal NAWM, thalamus and putamen nuclei of 12 patients with CIS, 12 with early RR-MS and 12 healthy controls using dynamic susceptibility contrast enhanced (DSC) T2*-weighted MRI.

RESULTS

Compared to controls, CBF was significantly decreased in the periventricular NAWM of CIS patients and in the periventricular NAWM and putamen of RR-MS patients. Compared to CIS, RR-MS patients showed a significant CBF decrease in the putamen.

CONCLUSIONS

CBF was decreased in the NAWM of both CIS and RR-MS patients and in the subcortical NAGM of RR-MS patients suggesting a continuum of tissue perfusion decreases beginning in white matter and spreading to gray matter, as the disease progresses.

Engineering angiogenesis following spinal cord injury: a coculture of neural progenitor and endothelial cells in a degradable polymer implant leads to an increase in vessel density and formation of the blood-spinal cord barrier

Angiogenesis precedes recovery following spinal cord injury and its extent correlates with neural regeneration, suggesting that angiogenesis may play a role in repair. An important precondition for studying the role of angiogenesis is the ability to induce it in a controlled manner. Previously, we showed that a coculture of endothelial cells (ECs) and neural progenitor cells (NPCs) promoted the formation of stable tubes in vitro and stable, functional vascular networks in vivo in a subcutaneous model. We sought to test whether a similar coculture would lead to the formation of stable functional vessels in the spinal cord following injury. We created microvascular networks in a biodegradable two-component implant system and tested the ability of the coculture or controls (lesion control, implant alone, implant + ECs or implant + NPCs) to promote angiogenesis in a rat hemisection model of spinal cord injury. The coculture implant led to a fourfold increase in functional vessels compared with the lesion control, implant alone or implant + NPCs groups and a twofold increase in functional vessels over the implant + ECs group. Furthermore, half of the vessels in the coculture implant exhibited positive staining for the endothelial barrier antigen, a marker for the formation of the blood-spinal cord barrier. No other groups have shown positive staining for the blood-spinal cord barrier in the injury epicenter. This work provides a novel method to induce angiogenesis following spinal cord injury and a foundation for studying its role in repair.

Neuromyelitis optica and asian phenotype of multiple sclerosis

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS), whereas neuromyelitis optica (NMO) is an inflammatory disease of the CNS selectively affecting the optic nerves and spinal cord. The pathological hallmark in MS is sharply demarcated demyelinating plaque with axons relatively preserved, whereas in NMO both axons and myelin are involved, resulting in necrotic cavitation. The nosological position of NMO has long been a matter of debate. In Asians, MS is rare; however, when it appears, the selective but severe involvement of the optic nerves and spinal cord is characteristic. This form, termed opticospinal MS (OSMS), has similar features to those of the relapsing form of NMO in Western populations. Recent discovery of a specific immunoglobulin G (IgG) against NMO, designated NMO-IgG, suggests that NMO is a distinct disease entity with a fundamentally different etiology from that of MS. Because NMO-IgG has been reported to be present in about 50%-60% of OSMS patients with longitudinally extensive spinal cord lesions (LESCLs), OSMS in Asians has been suggested to be the same entity as NMO. About half of the patients with the anti-aquaporin 4 (AQP4) antibody demonstrate brain lesions fulfilling the Barkhof criteria, whereas OSMS patients without the anti-AQP4 antibody show significantly fewer brain lesions. These findings indicate that the mechanism of LESCLs in Asians is heterogeneous, both related and unrelated to anti-AQP4 antibody, and that the disease condition with anti-AQP4 antibody does not completely overlap OSMS in Asians. This review discusses possible mechanisms for OSMS and anti-AQP4 autoimmune syndrome of the CNS.

Association of the HLA-DRB1 alleles with characteristic MRI features of Asian multiple sclerosis

Background

In Asian patients with multiple sclerosis (MS), a paucity of brain lesions and longitudinally extensive spinal cord lesions (LESCLs) extending three or more vertebral segments are characteristic findings on magnetic resonance imaging (MRI). We aimed to disclose possible factors contributing to the development of such MRI features.

Method

Genotyping of HLA-DRB1 and -DPB1 alleles was performed in 121 consecutive Japanese patients with clinically definite MS based on the Poser criteria and 125 healthy controls. Possible factors associated with MRI features were determined by multiple logistic analysis. Patients with MS were classified based on the presence or absence of brain lesions fulfilling the Barkhof criteria (Barkhof brain lesions) and LESCLs. Barkhof brain lesion–negative (−) patients had a markedly lower frequency of HLA-DRB1*0901 than controls ( Pcorr < 0.05), whereas the frequency of DRB1*1501 was increased in the Barkhof brain lesion–positive (+) group, although this increase was not significant after correction. No Barkhof(−)LESCL(+) patients carried DRB1*0901 ( Pcorr < 0.05), despite this being the most common allele in Japanese. The Barkhof(−)LESCL(−) group showed a significant increase in the frequency of DRB1*0405 compared with controls ( Pcorr < 0.05). None of the DPB1 alleles were significantly different among the groups. Using multiple logistic analysis, the absence of oligoclonal bands was positively associated with an absence of Barkhof brain lesions, whereas a higher EDSS score was positively associated with the presence of LESCLs; however, the presence of anti-aquaporin-4 antibodies was not associated with either feature.

Conclusion

The characteristic MRI features in Asians are partly related to distinct HLA-DRB1 gene alleles and an absence of oligoclonal bands.

Temporal changes and geographical differences in multiple sclerosis phenotypes in Japanese: nationwide survey results over 30 years

Background

There are two distinct phenotypes of multiple sclerosis (MS) in Asians, manifesting as optic-spinal (OSMS) and conventional (CMS) forms. In Japan, four nationwide surveys of MS have been conducted. The first three were in 1972, 1982, and 1989, and we performed the fourth in 2004.

Results

The recent survey showed six main findings as follows: (1) a four-fold increase in the estimated number of clinically definite patients with MS in 2003 (9900; crude MS prevalence, 7.7/100,000) compared with 1972; (2) a shift in the peak age at onset from early 30s in 1989 to early 20s in 2003; (3) a successive proportional decrease in optic-spinal involvement in clinically definite patients with MS; (4) a significant north–south gradient for the CMS/OSMS ratio; (5) after subdivision of the mainland (30–45° North) into northern and southern parts at 37°N, northern-born northern residents (northern patients) showed a significantly higher CMS/OSMS ratio and higher frequency of brain lesions fulfilling the Barkhof criteria (Barkhof brain lesions) than southern-born southern residents (southern patients); (6) among northern patients, the absolute numbers of patients with CMS and those with Barkhof brain lesions rapidly increased with advancing birth year.

Conclusions

These findings suggest that MS phenotypes are drastically altered by environmental factors, such as latitude and “Westernization.”

Luteolin inhibits myelin basic protein-induced human mast cell activation and mast cell-dependent stimulation of Jurkat T cells

BACKGROUND AND PURPOSE

Allergic inflammation and autoimmune diseases, such as atopic dermatitis, psoriasis and multiple sclerosis (MS), involve both mast cell and T-cell activation. However, possible interactions between the two and the mechanism of such activations are largely unknown.

EXPERIMENTAL APPROACH

Human umbilical cord blood-derived cultured mast cells (hCBMCs) and Jurkat T cells were incubated separately or together, following activation with myelin basic protein (MBP), as well as with or without pretreatment with the flavonoid luteolin for 15 min. The supernatant fluid was assayed for inflammatory mediators released from mast cells and interleukin (IL)-2 release from Jurkat cells.

KEY RESULTS

MBP (10 microM) stimulates hCBMCs to release IL-6, IL-8, transforming growth factor (TGF)-beta1, tumour necrosis factor-alpha (TNF-alpha), vascular endothelial growth factor (VEGF), histamine and tryptase (n=6, P<0.05). Addition of mast cells to Jurkat cells activated by anti-CD3/anti-CD28 increases IL-2 release by 30-fold (n=3, P<0.05). MBP-stimulated mast cells and their supernatant fluid further increase Jurkat cell IL-2 release (n=3, P<0.05). Separation of mast cells and activated Jurkat cells by a Transwell permeable membrane inhibits Jurkat cell stimulation by 60%. Pretreatment of Jurkat cells with a TNF-neutralizing antibody reduces IL-2 release by another 40%. Luteolin pretreatment inhibits mast cell activation (n=3-6, P<0.05), Jurkat cell activation and mast cell-dependent Jurkat cell stimulation (n=3, P<0.05).

CONCLUSIONS AND IMPLICATIONS

Mast cells can stimulate activated Jurkat cells. This interaction is inhibited by luteolin, suggesting that this flavonoid may be useful in the treatment of autoimmune diseases.

Atopic myelitis with focal amyotrophy: a possible link to Hopkins syndrome

Among 22 consecutive patients with myelitis, of unknown etiology, and atopic diathesis (atopic myelitis) who from April 2002 to March 2006 had been studied in our clinic, 5 (23%) showed focal amyotrophy in one or two limbs. These 5 patients were subjected to combined clinical, electrophysiological, neuroimaging and immunological studies. Ages were 18 to 58-years-old (average 39). Four showed amyotrophy of unilateral or bilateral upper limbs while one showed amyotrophy in both thighs. All patients showed on-going denervation potentials in the affected muscles, while motor conduction study including F wave was normal except for in one patient who showed prolonged F wave latency in one nerve. Two had localized high signal intensity lesions involving anterior horns on spinal cord MRI and three showed abnormalities suggesting pyramidal tract involvement on motor evoked potentials. All had a present and/or past history of atopic disorders and specific IgE against common environmental allergens, such as mite antigens and cedar pollens, and four showed mild eosinophilia, all of which were compatible with atopic myelitis. When clinical and laboratory findings were compared between atopic myelitis with (n=5) or without focal amyotrophy (n=17), the former showed a significantly higher frequency of present and past history of asthma (80% vs. 24%, p=0.0393) and tended to have higher EDSS scores (3.8+/-1.6 vs. 3.1+/-1.4). Two patients showed mild to moderate improvements after immunotherapies such as methylprednisolone pulse therapy or plasma exchange, while two recovered with low dose corticosteroids and one without treatment had a gradually progressive course. Although atopic myelitis preferentially involves the posterior column of the cervical spinal cord, it is possible that anterior horn cells are affected in some cases of atopic myelitis, especially in patients with asthma. This suggests a possible link between atopic myelitis and Hopkins syndrome (asthmatic amyotrophy).

Devic’s neuromyelitis optica: a critical review

Devic's neuromyelitis optica (NMO) is an idiopathic inflammatory demyelinating and necrotizing disease characterized by predominant involvement of the optic nerves and spinal cord. In Asian countries relapsing NMO has been known as opticospinal multiple sclerosis. It has long been debated if NMO is a variant of multiple sclerosis (MS) or a distinct disease. Recent studies have shown that NMO has more frequently a relapsing course, and results from attack to aquaporin-4 which is the dominant water channel in the central nervous system, located in foot processes of the astrocytes. Distinctive pathological features of NMO include perivascular deposition of IgG and complement in the perivascular space, granulocyte and eosinophil infiltrates and hyalinization of the vascular walls. These features distinguish NMO from other demyelinating diseases such as MS and acute demyelinating encephalomyelopathy. An IgG-antibody that binds to aquaporin-4, named NMO-IgG has high sensitivity and specificity. Magnetic resonance imaging (MRI) studies have revealed that more frequently there is a long spinal cord lesion that extends through three or more vertebral segments in length. Brain MRI lesions atypical for MS are found in the majority of cases. Treatment in the acute phase includes intravenous steroids and plasma exchange therapy. Immunosupressive agents are recommended for prophylaxis of relapses.

Anterior periventricular linear lesions in optic-spinal multiple sclerosis: a combined neuroimaging and neuropathological study

There are two distinct subtypes of multiple sclerosis (MS) in Asians, optic-spinal (OSMS) and conventional (CMS). In OSMS, severe spinal cord lesions are characteristic while brain lesions are scant. We sought to clarify atypical brain lesions in OSMS by neuroimaging and pathological studies. For brain MRI, 124 consecutive Japanese patients with clinically definite MS based on Poser criteria were enrolled, 57 with OSMS and 67 with CMS. Ten autopsied cases (seven OSMS and three CMS) were studied pathologically. Although the frequency of brain lesions fulfilling Barkhof criteria was significantly higher in CMS than in OSMS, periventricular linear lesions along with the anterior portion of the corpus callosum and the lateral ventricles were significantly more common in OSMS than in CMS. Pathologically, periventricular lesions in CMS extended deeply into the white matter, while those in OSMS were confined to periventricular areas. T cell infiltration in lesions was prominent in CMS but not in OSMS. Although severe axonal loss and cavity formation were commonly seen in periventricular and spinal cord lesions in OSMS, lymphocytic infiltrates and vessel wall thickening were observed only in the latter. Thus, we suggested that anterior periventricular linear lesions without ovoid ones are characteristic of OSMS.

Proteomic analysis of human cerebral endothelial cells activated by multiple sclerosis serum and IFNbeta-1b

Several groups have recently described the endothelial cell (EC) as an important target of pathological mediators in multiple sclerosis (MS). Despite the recognition of the EC as a significant target in MS and a possible beneficiary of Beta-interferon therapy, the structural changes which occur in the cerebrovascular endothelium and the effects of interferon-beta 1b on these changes have not been closely evaluated. Disruption or dysregulation of the blood brain barrier (BBB) in MS represents a loss of endothelial integrity, which may facilitate the transendothelial migration of activated leukocytes responsible for the development of demyelinating lesions of MS. We used proteomics (2-dimensional gel electrophoresis and MALDI-MS) to characterize the effects of serum from MS patients with active disease (with and without interferon-beta 1b therapy) on human cerebral endothelial cells. The results of this study revealed the up- and down-regulation of expression of several proteins related to blood vessel development, cell structure, and cell cycle control. Using this approach we have identified protein 14-3-3, metavinculin, myosin-9, plasminogen, reticulocalbin-2 and-3, ribonuclease/angiogenin inhibitor 1, annexin A1, tropomyosin and Ras-related protein Rap-1A as potential new markers of active MS disease. A more complete description of cerebrovascular endothelial biomarkers and mediators in MS pathogenesis and how they are regulated by inflammatory cytokines and beta-interferons may lead to the development of more effective therapies and more accurate diagnostic markers in MS.

Heterogeneity and continuum of multiple sclerosis in Japanese according to magnetic resonance imaging findings

There are two distinct subtypes of multiple sclerosis (MS) in Asians: optic-spinal (OSMS) and conventional (CMS). Longitudinally extensive spinal cord lesions (LESCLs) extending over three or more vertebral segments are characteristic of patients with OSMS, yet in Asians, one-fourth of CMS patients also have LESCLs. To clarify the distinction between LESCLs in OSMS and CMS, and to characterize the relationship between the presence of LESCLs and brain magnetic resonance imaging (MRI) findings, we studied 142 patients with clinically definite MS of relapsing-remitting onset and 12 patients with primary progressive MS (PPMS) by MRI of the whole spinal cord and brain. The former was diagnosed by Poser criteria, including 57 with OSMS, 67 with CMS and 18 with brainstem-spinal form of MS, while the latter by McDonald criteria. The presence of LESCLs throughout the entire clinical course was significantly more common in OSMS patients than in CMS patients, while brain lesions fulfilling the Barkhof criteria (Barkhof brain lesions) were significantly more common in CMS patients than OSMS patients. LESCLs in OSMS patients most frequently affected the upper to middle thoracic cord, with either holocord or central gray matter involvement. By contrast, 70% of LESCLs in CMS patients predominantly affected the peripheral white matter of the mid-cervical cord. LESCLs in patients with PPMS also showed preferential involvement of the peripheral white matter of the mid-cervical cord. One-third of OSMS patients had neither LESCLs nor Barkhof brain lesions more than 10 years after disease onset, and showed significantly milder disability than OSMS patients with LESCLs. These findings suggest that LESCLs are heterogeneous between OSMS and CMS patients, and that there are distinct subtypes of MS in Japanese, according to clinical and MRI findings.

Previous treatment with ebselen and vitamin E alters adenine nucleotide hydrolysis in platelets from adult rats experimentally demyelinated with ethidium bromide

Many aspects of the relationship between the demyelinating pathology and platelet function need to be elucidated. Thus, the activity of NTPDase and 5'-nucleotidase enzymes was analyzed in platelets from rats demyelinated with ethidium bromide (EB) and previously treated with ebselen (Ebs) and vitamin E (Vit. E). The animals were divided into four groups: for ebselen, the groups were: I-control (saline), II-(saline and Ebs), III-(EB) and IV-(EB and Ebs); and for vitamin E, the groups were: I - control (saline), II-(saline and Vit. E), III-(EB) and IV-(EB and Vit. E). After 3 and 21 days, the blood was collected and the platelets were separated for enzymatic assays. For the treatment with Ebs, the NTPDase activity for ATP substrate was significantly lower in groups II, III and IV (p < 0.05) after 3 days, while after 21 days, a reduction was observed in group III (p < 0.05). ADP hydrolysis was reduced in group II (p < 0.05) and increased in group IV (p < 0.05) after 3 days, while after 21 days there was an increase in group IV (p < 0.05). In the treatment with Vit. E, ATP hydrolysis was lower in groups II, III and IV (p < 0.05) after 3 and 21 days. ADP hydrolysis was increased in group II (p < 0.05) after 3 days, and in group IV (p < 0.05) after 21 days. However, 5'-nucleotidase activity was not altered by the treatments. These findings demonstrate that NTPDase activity in platelets is diminished in demyelinating events and the treatments with Ebs and Vit. E modulated adenine nucleotide hydrolysis.

Vascular Endothelial Growth Factor (VEGF) in Autoimmune Diseases

Vascular endothelial growth factor (VEGF) is a potent stimulating factor for angiogenesis and vascular permeability. There are eight isoforms with different and sometimes overlapping functions. The mechanisms of action are under investigation with emerging insights into overlapping pathways and cross-talk between other receptors such as the neuropilins, which were not previously associated to angiogenesis. VEGF has important physiological actions on embryonic development, healing, and menstrual cycle. It also has a great role in pathological conditions that are associated to autoimmune diseases. There is considerable evidence in various autoimmune diseases such as in systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis of an interrelationship between the VEGF system and theses disorders. Serum levels of VEGF correlate with disease activity in a large number of autoimmune diseases and fall with the use of standard therapy. We raised the possible future therapeutic strategies in autoimmune diseases with the anti-VEGF or anti-VEGFR (receptor). So far, this therapy has been used in cancer and macular ocular degeneration in diabetes. This review outlines the evidence for VEGF participation in various autoimmune diseases and proposes lines for future research in this field.

A distinct subgroup of chronic inflammatory demyelinating polyneuropathy with CNS demyelination and a favorable response to immunotherapy

To explore subclinical central nervous system (CNS) involvement in chronic inflammatory demyelinating polyneuropathy (CIDP), we recorded somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) using transcranial magnetic stimulation, to measure central sensory conduction time (CSCT) and central motor conduction time (CMCT) and examined brain and spinal cord MRI in patients with probable CIDP based on the American Academy of Neurology AIDS Task Force criteria. Eighteen patients with probable CIDP (12 males and 6 females; mean age at examination+/-SD, 45.8+/-17.0 years; range, 17-72) were included in the study. Of the 13 patients who underwent SEPs, one had prolonged CSCT (8%) and of the 13 who underwent MEPs, four had abnormal CMCT (31%). Cranial MRI revealed five of 18 patients had abnormal scans, only one of which showed multiple ovoid periventricular lesions suggestive of demyelination while none showed any intramedullary lesion on spinal cord MRI. Thus, 6 of the 18 patients were considered to have subclinical demyelinative CNS involvement which had lower disability on Global Neurological Disability Score (GNDS) (p=0.0061), a male preponderance (0.0537) and a larger compound muscle action potential (CMAP) amplitude in the median nerve (p=0.005) than those without. The decrease of GNDS with immunologic therapies was nearly significant in the former (p=0.0556) but not in the latter. The results of the present study suggest that subclinical CNS involvement in CIDP is not uncommon in Japanese patients and that CIDP with subclinical CNS involvement is more demyelinative thus responsive to immunotherapies while those without have more axonal damage and less responsive to immunotherapies.

Helicobacter pylori infection is a potential protective factor against conventional multiple sclerosis in the Japanese population

Persistent Helicobacter pylori (H. pylori) infection is a chronic inflammatory stimulus to hosts with an inverse correlation to atopic disorders. In this study, a total of 105 consecutive multiple sclerosis (MS) patients were divided into 52 opticospinal MS (OSMS) and 53 conventional MS (CMS), and their sera, along with those from 85 healthy controls (HC), were examined by an enzyme-linked immunosorbent assay using antibodies against H. pylori. H. pylori seropositivity was significantly lower in patients with CMS (22.6%) compared with HC (42.4%) and patients with OSMS (51.9%) (p=0.0180 and p=0.0019, respectively). In patients with CMS, H. pylori seropositivity showed a significant inverse association with mean EDSS score and fulfillment of McDonald MRI criteria for space (OR=0.61, p=0.0344 and OR=0.11, p=0.0297). These findings suggest that H. pylori infection is a protective factor against CMS in Japanese.

IL-1beta regulates blood-brain barrier permeability via reactivation of the hypoxia-angiogenesis program

Loss of blood-brain barrier (BBB) integrity is believed to be an early and significant event in lesion pathogenesis in the inflammatory demyelinating disease multiple sclerosis (MS), and understanding mechanisms involved may lead to novel therapeutic avenues for this disorder. Well-differentiated endothelium forms the basis of the BBB, while astrocytes control the balance between barrier stability and permeability via production of factors that restrict or promote vessel plasticity. In this study, we report that the proinflammatory cytokine IL-1beta, which is prominently expressed in active MS lesions, causes a shift in the expression of these factors to favor plasticity and permeability. The transcription factor, hypoxia inducible factor-1 (HIF-1), plays a significant role in this switch. Using a microarray-based approach, we found that in human astrocytes, IL-1beta induced the expression of genes favoring vessel plasticity, including HIF-1alpha and its target, vascular endothelial growth factor-A (VEGF-A). Demonstrating relevance to MS, we showed that HIF-1alpha and VEGF-A were expressed by reactive astrocytes in active MS lesions, while the VEGF receptor VEGFR2/flk-1 localized to endothelium and IL-1 to microglia/macrophages. Suggesting functional significance, we found that expression of IL-1beta in the brain induced astrocytic expression of HIF-1alpha, VEGF-A, and BBB permeability. In addition, we confirmed VEGF-A to be a potent inducer of BBB permeability and angiogenesis, and demonstrated the importance of IL-1beta-induced HIF-1alpha in its regulation. These results suggest that IL-1beta contributes to BBB permeability in MS via reactivation of the HIF-VEGF axis. This pathway may represent a potential therapeutic target to restrict lesion formation.

NTPDase and 5'-nucleotidase activities in physiological and disease conditions: new perspectives for human health

Extracellular nucleotides and nucleosides act as signaling molecules involved in a wide spectrum of biological effects. Their levels are controlled by a complex cell surface-located group of enzymes called ectonucleotidases. There are four major families of ectonucleotidases, nucleoside triphosphate diphosphohydrolases (NTPDases/CD39), ectonucleotide pyrophosphatase/phosphodiesterases (E-NPPs), alkaline phosphatases and ecto-5'-nucleotidase. In the last few years, substantial progress has been made toward the molecular identification of members of the ectonucleotidase families and their enzyme structures and functions. In this review, there is an emphasis on the involvement of NTPDase and 5'-nucleotidase activities in disease processes in several tissues and cell types. Brief background information is given about the general characteristics of these enzymes, followed by a discussion of their roles in thromboregulatory events in diabetes, hypertension, hypercholesterolemia and cancer, as well as in pathological conditions where platelets are less responsive, such as in chronic renal failure. In addition, immunomodulation and cell-cell interactions involving these enzymes are considered, as well as ATP and ADP hydrolysis under different clinical conditions related with alterations in the immune system, such as acute lymphoblastic leukemia (ALL), B-chronic lymphocytic leukemia (B-CLL) and infections associated with human immunodeficiency virus (HIV). Finally, changes in ATP, ADP and AMP hydrolysis induced by inborn errors of metabolism, seizures and epilepsy are discussed in order to highlight the importance of these enzymes in the control of neuronal activity in pathological conditions. Despite advances made toward understanding the molecular structure of ectonucleotidases, much more investigation will be necessary to entirely grasp their role in physiological and pathological conditions.

Decreased Expression of VEGF-A in Rat Experimental Autoimmune Encephalomyelitis and in Cerebrospinal Fluid Mononuclear Cells from Patients with Multiple Sclerosis

Vascular endothelial growth factor A (VEGF-A) stimulates angiogenesis, but is also pro-inflammatory and plays an important role in the development of neurological disease, where it can have both attenuating and exacerbating effects. VEGF-B, a related molecule, is highly expressed in the central nervous system and seems to be important in neurological injury. A few studies have indicated that VEGF-A may play a role in the pathogenesis of multiple sclerosis (MS), but the role of VEGF-B has not been studied. We have studied the expression of VEGF-A, -B and their receptors by mRNA in situ hybridization, immunohistochemistry and real-time PCR in spinal cord from LEW rats with experimental autoimmune encephalomyelitis (EAE) and in cerebrospinal fluid (CSF) and blood samples from MS patients. Whereas VEGF-A is downregulated in glia in EAE, the infiltrating inflammatory cells are positive for VEGF-A. Expression of VEGF-B and the VEGF receptors is unaltered. In addition, the levels of VEGF-A mRNA in mononuclear cells [corrected] in CSF are lower in MS patients compared with controls. These results demonstrate a complex regulation of VEGF-A during neuroinflammation and suggest that VEGF-B is not involved in the pathogenesis of MS.

Blood-Brain Barrier Imaging and Therapeutic Potentials

Much work has been done in the last several decades to improve the understanding of the molecular composition of the blood-brain barrier (BBB). Advances in magnetic resonance imaging have resulted in development of dynamic magnetic resonance imaging techniques to quantify permeability measurements across the brain endothelium. This review describes the basic anatomical and biochemical concepts of a BBB and the various techniques for magnetic resonance measurement of BBB permeability. To date, BBB permeability data have been shown to be useful in preoperative brain tumor grading and potentially also in determining the effectiveness of selective types of therapy. Explorative studies are evaluating new strategies for safe and effective altering of the BBB permeability to improve local drug delivery into brain tumors. As new antiangiogenesis drugs become available, BBB permeability imaging may also become critical as a surrogate angiogenesis marker to monitor tumor response to these agents. Finally, BBB permeability data may also prove useful in future applications to guide therapy in other nontumoral disease processes such as acute cerebral ischemia and inflammatory processes such as multiple sclerosis.