The stimulator of interferon genes (STING) pathway is upregulated in striatal astrocytes of patients with multiple system atrophy.

Multiple system atrophy (MSA) is a progressive neurodegenerative disorder characterized by the accumulation of pathogenic phosphorylated α-synuclein in oligodendrocytes. In brains affected by MSA, severe astrogliosis is also observed, but its precise role in MSA pathogenesis remains largely unknown. Recently, the stimulator of interferon genes (STING) pathway and type I interferons, its downstream molecules, have been reported to be involved in the neurodegenerative process and to be activated in astrocytes. This study aimed to investigate the role of the STING pathway in the pathogenesis of MSA using postmortem brains. Samples used for immunohistochemical analysis included 6 cases of MSA parkinsonism type (MSA-P), 6 cases of MSA cerebellar type (MSA-C), and 7 age-matched controls. In MSA-P cases, astrocytes immunopositive for STING and TANK-binding kinase 1 (TBK1), its downstream molecule, were abundantly observed in the putamen and the substantia nigra. Moreover, these molecules colocalized with glial fibrillary acidic protein (GFAP) in reactive astrocytes, and the density of STING-positive astrocytes correlated with that of GFAP-positive reactive astrocytes in the brains of patients with MSA-P. These results suggest that the upregulated expression of STING pathway-related proteins in astrocytes and the subsequent inflammation may contribute to the pathogenesis in MSA-P and could provide novel therapeutic targets for the treatment of MSA.

Long-term post-mortem studies following neurturin gene therapy in patients with advanced Parkinson's disease.

We performed post-mortem studies on two patients with advanced Parkinson's disease 8 and10 years following AAV2-neurturin (CERE120) gene therapy, the longest post-mortem trophic factor gene therapy cases reported to date. CERE120 was delivered to the putamen bilaterally in one case (10 years post-surgery), and to the putamen plus the substantia nigra bilaterally in the second (8 years post-surgery). In both patients there was persistent, albeit limited, neurturin expression in the putamen covering ∼3-12% of the putamen. In the putamen, dense staining of tyrosine hydroxylase-positive fibres was observed in areas that contained detectable neurturin expression. In the substantia nigra, neurturin expression was detected in 9.8-18.95% and 22.02-39% of remaining melanin-containing neurons in the patient with putamenal and combined putamenal and nigral gene delivery, respectively. Melanized neurons displayed intense tyrosine hydroxylase and RET proto-oncogene expression in nigral neurons in the patient where CERE120 was directly delivered to the nigra. There was no difference in the degree of Lewy pathology in comparison to untreated control patients with Parkinson's disease, and α-synuclein aggregates were detected in neurons that also stained for neurturin, RET, and tyrosine hydroxylase. These changes were not associated with antiparkinsonian benefits likely due to the limited neurturin expression. This study provides the longest term evidence of persistent transgene expression following gene delivery to the CNS and the first human results when targeting both the terminal fields in the putamen as well as the originating nigral neurons.

Multilevel analysis of neuropathogenesis of neurocognitive impairment in HIV.

The neuropathogenesis of HIV-associated neurocognitive disorders (HAND) remains puzzling. We interrogated several levels of data (host genetic, histopathology, brain viral load, and neurocognitive) to identify histopathological changes most relevant to HAND. The design of the study is a clinicopathological study employing genetic association analyses. Data and brain tissue from 80 HIV-infected adults were used. Markers in monocyte chemoattractant protein-1 (MCP-1), interleukin 1-alpha (IL1-α), macrophage inflammatory protein 1-alpha (MIP1-α), DRD3, DRD2, and apolipoprotein E (ApoE) were genotyped. Microtubule associated protein 2 (MAP2), synaptophysin (SYP), human leukocyte antigen-DR (HLA-DR), glial fibrillary acidic protein (GFAP), amyloid beta (A-Beta), and ionized calcium-binding adaptor molecule-1 (Iba-1) immunoreactivity were quantified in the frontal cortex, putamen, and hippocampus. A composite score for each marker (mean of the three brain regions) was used. Neurocognitive functioning and other clinical variables were determined within 1 year of death. Brain HIV RNA viral load was available for a subset of cases. MAP2 and SYP proved most relevant to neurocognitive functioning. Immunoreactivity of these markers, as well as A-Beta and Iba-1, was correlated with brain HIV RNA viral load. Several genetic markers in combination with other factors predicted histopathology: HIV blood viral load, MIP1-α genotype, and DRD3 genotype predicted Iba-1 immunoreactivity; the duration of infection and IL1-α genotype predicted GFAP immunoreactivity; ApoE genotype and age at death predicted A-Beta immunoreactivity. These data indicate that HIV replication in the brain is the primary driving force leading to neuroinflammation and dysfunctional protein clearance, as reflected by A-Beta and Iba-1. Downstream to these changes are synaptodendritic degeneration, which is the immediate histopathological substrate of the neurocognitive impairment characteristic of HAND. These intermediate histopathological phenotypes are influenced by host genetic polymorphisms in genes encoding cytokines/chemokines, neuronal protein clearance pathways, and dopaminergic factors.

Striatal microinfusion of Tourette syndrome and PANDAS sera: failure to induce behavioral changes.

Rodent striatal microinfusions have been suggested as a model for assessing the behavioral effects induced by antineuronal antibodies. We used this approach to evaluate the proposed autoimmune etiology for Tourette syndrome (TS) and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS). Sera were assessed from patients with TS (n = 9) preselected based on the presence of elevated enzyme-linked immunosorbent assay optical densities against putamen homogenate and sera from patients with PANDAS (n = 8), selected from a larger group assayed for antibodies against a putamen synaptosomal preparation. The effect of antibodies against the streptococcal M5 protein were also studied. A total of 44 Fischer rats received bilateral infusion of sera: 23 ventral striatum (5 PANDAS, 5 TS, 5 anti-M5 protein, and 8 control); 21 ventrolateral striatum (5 PANDAS, 5 TS, 5 anti-M5 protein, and 6 controls). Cannulas were placed bilaterally and symmetrically by stereotactic techniques. After animals were allowed to recover for 1 week, sera were microinfused for 3 days. Animal behavior was then simultaneously quantified by daily observation and monitoring using automated activity boxes for 10 days after infusion. No significant alterations in stereotypic behavior or movement were observed between the PANDAS, TS, or anti-M5 protein and control groups. Our findings are in contrast to previous reports, and suggest the need for further investigations to determine the validity of the model and of autoimmune-mediated hypotheses for pediatric movement disorders.

Antibodies against human putamen in adolescents with anorexia nervosa.

OBJECTIVE: To examine whether antiputamen antibodies are present in adolescents with anorexia nervosa (AN). METHOD: Using enzyme-linked immunosorbent assay (ELISA) with an extract of human putamen as an antigen, sera samples obtained from 22 adolescents with active AN and from 22 healthy adolescents (control group) were assayed for antibodies to neuronal components RESULTS: Mean optical density (OD) readings for serum antibodies against human putamen in adolescents with AN was significantly greater than the mean OD readings in the control group (0.492 +/- 0.086 vs. 0.275 +/- 0.028, p =.02). When serum positivity was defined as an OD level greater than 2 SD above the mean control group value (0.541), antiputamen antibodies were detected in the blood of 6 AN patients (27%) whereas they were detected in the blood of 1 patient (5%) in the control group (p <.05; Fisher's exact test). DISCUSSION: The detection of antiputamen antibodies in adolescents with AN suggests an underlying immune process at the putamen level in some patients with this eating disorder.

Restricted unilateral Sydenham's chorea: reversible contralateral striatal hypermetabolism demonstrated on single photon emission computed tomographic scanning.

Sydenham's chorea results from group A streptococcus infection and subsequent generation of antineuronal antibodies directed at the caudate nucleus and putamen. Predominantly bilateral, in up to 30% of cases the chorea can be unilaterally restricted. Imaging studies, both structural (magnetic resonance imaging) and functional (positron emission tomography), in patients with bilateral Sydenham's chorea have suggested reversible striatal abnormalities. Two patients with unilateral Sydenham's chorea are presented. Computed tomographic and magnetic resonance imaging were normal in both. However, hexamethylpropylenamine oxime single photon emission tomographic (HMPAO SPECT) studies demonstrated hypermetabolism in the contralateral basal ganglia. Resolution of symptoms in one of the patients coincided with normalization of the SPECT scan. Thus, unilateral striatal hypermetabolism appears to underlie the contralateral chorea observed. A SPECT scan probably should be included in the work-up of new-onset chorea.

Spatiotemporal expression gradients of the carbohydrate antigen (CD15) (Lewis X) during development of the human basal ganglia.

The developmental expression pattern of the carbohydrate epitope CD15 (Lewis X, Le X) (alpha1-->3-fucosyl-N-acetyl-lactosamine) has been immunocytochemically evaluated in paraffin sections within the human basal ganglia from 10 weeks gestation to three years after birth. At 11 weeks of gestation, CD15 (Le X) positive radial glial cells were located in the anterior and dorsal parts of the lateral ganglionic eminence. Their processes ran from the subventricular zone radially in a highly ordered fashion to the dorsolateral margin of the caudate nucleus and further to the lateral rim of the putamen. At 12 weeks of gestation, strands of CD15 (Le X) material continued to the pial surface, forming a continuous CD15 (Le X) positive borderline separating the accumbens nucleus and olfactory tubercle from the piriform cortex. At 13 weeks of gestation the dorsal putamen was completely CD15 (Le X) immunoreactive along its perimeter and CD15 (Le X) patches, consisting of fine granular material, appeared at the dorsolateral margin of the putamen at this age; while the first CD15 (Le X) patches in the caudate nucleus were observed four weeks later. The matrix compartment of the caudate and dorsal putamen became gradually stained by granular CD15 (Le X) positive material into which CD15 (Le X) immunoreactive somata were embedded. The striking contrast in staining between patch and matrix compartments disappeared shortly after birth. The ventral striatum did not become immunoreactive until the last few weeks before birth. After the formation of CD15 (Le X) positive patches in the striatum (from 12 weeks of gestation), delicate CD15 (Le X) fibres, often accumulated in bundles and related to the striatal patches, became apparent coursing towards the external pallidal lamina and the globus pallidus. Immunoreactivity in the globus pallidus itself was transient, emerging from 16 weeks of gestation, reaching a peak at 21 weeks of gestation and disappearing by birth. Both processes, i.e. the occurrence of CD15 (Le X) striatopallidal fibres and the emerging immunoreactivity in their pallidal target, may be interrelated, so that ingrowing CD15 (Le X) positive axons from the striatum provoke CD15 (Le X) expression in the external and internal pallidum. The variable patterns and intensities of CD15 (Le X) expression are possibly related to periods of maturation of the striatum and the establishment of functional interactions within the basal ganglia. Differential staining of patch and matrix in the developing neostriatum suggests that a distinct phase of cellular adhesion or dishesion mediated by the CD15 (Le X) epitope occurs during establishment of the patch and matrix regions.

Antibodies against human putamen in children with Tourette syndrome.

BACKGROUND: Similar to the model for Sydenham's chorea, antineuronal antibodies, which develop in response to a preceding streptococcal infection, have been speculated to have a role in the development of Tourette syndrome (TS). METHODS: Serum antibodies against human caudate, putamen, and globus pallidus (interna and externa) were assayed by enzyme-linked immunosorbent assay (ELISA) and Western blot techniques and results were correlated with clinical characteristics and markers of streptococcal infection. SUBJECTS: A total of 41 children with TS (mean age, 11.3 years) and 39 controls (mean age, 12.1 years) were included. RESULTS: Compared with controls, TS subjects had a significant increase in the mean (p=0.006) and median (p=0.002) ELISA optical density (OD) levels of serum antibodies against putamen, but not caudate or globus pallidus. Western blots on 20 control and 20 TS serum samples showed that specific antibodies to caudate/putamen occurred more frequently in TS subjects at 83, 67, and 60 kDa; antigens were present in a synaptosomal fraction. TS subjects with a positive family history of tics had higher OD values (p < or = 0.04), but no association was shown with age of tic onset, tic severity, sudden onset of tics, or presence of attention-deficit hyperactivity disorder or obsessive-compulsive disorder. Risk ratio calculations in TS and control groups and in study subjects dichotomized for high and low putamen OD values were similar for titers of antistreptolysin O > or = 166 or antideoxyribonuclease B > or = 170. A subgroup analysis limited to subjects with elevated streptococcal titers, however, showed a significantly (p < or = 0.004) larger number of TS subjects with elevated OD levels. CONCLUSION: Children and adolescents with TS had significantly higher serum levels of antineuronal antibodies against putamen than did controls, but their relation to clinical characteristics and markers for streptococcal infection remains equivocal.

Localization of the brain lesion affects the lateralization of T-lymphocyte dependent cutaneous inflammation. Evidence for an immunoregulatory role of the right frontal cortex-putamen region.

We have previously demonstrated that brain lesions caused by stroke led to the lateralization of T-cell dependent inflammation. The purpose of this study was to assess the impact of localization of the brain lesion on lateralization of immune responsiveness. The delayed-type hypersensitivity (DTH) reaction was used as an in vivo measure of antigen specific T-lymphocyte reactivity. All stroke patients were examined with computed scan tomography (CT) of the brain to ascertain the localization and extent of the brain lesion. Patients with right-sided brain lesions displayed significantly larger (P = 0.008) DTH responses on the paretic side compared to the contralateral side. Detailed analysis of the localization of the brain lesion revealed that infarcts encompassing frontal lobe-putamen led to significantly larger (P = 0.007) DTH responses on the paretic side compared to the contralateral side. Localization of the brain lesion affects the lateralization of DTH, supporting an asymmetrical modulation of the immune response. In addition, our study points to the frontal cortex-putamen as a putative brain centre regulating the magnitude of immune responses.

Antineuronal antibodies: tics and obsessive-compulsive symptoms.

Fluorescent serum antibody determinations were used to examine whether children with obsessive-compulsive disorder (OCD) or less pervasive obsessive-compulsive symptoms (OCS) would show evidence of caudate nucleus involvement. Recent studies of OCD have documented smaller caudate nucleus volumes in adults with childhood onset than in normal controls, but not smaller putamen volumes. Thirty-eight cases were recruited from an ongoing study of childhood neurodevelopmental disorders. Nineteen samples from clinical cases had existing or previously documented OCS and attention-deficit hyperactivity disorder (ADHD) with or without concomitant tics. Nineteen additional clinical controls with ADHD, but without tics or OCS, were identified. The sera from clinical cases showed antibodies directed against caudate [odds ratio (OR) 2.0; 95% confidence interval (CI) 1.0 to 4.1], putamen (OR 3.0; 95% CI 1.5 to 5.8), or both (OR 2.9; 95% CI 1.58 to 5.7) at a rate significantly higher than that of clinical controls, providing evidence of basal ganglia involvement in OCS. These preliminary data do not support a differential effect against caudate compared to putamen for these children, but suggest a more generalized central nervous system response.

Cellular basis for interactions between catecholaminergic afferents and neurons containing Leu-enkephalin-like immunoreactivity in rat caudate-putamen nuclei.

Dopaminergic afferents to the dorsal striatum, caudate-putamen nuclei, are known to modulate the levels and synthesis of endogenous opiate peptides (Leu5 and Met5-enkephalins). We examined the dual immunocytochemical localization of antisera raised against Leu5-enkephalin and the catecholamine-synthesizing enzyme, tyrosine hydroxylase (TH), to determine the cellular substrates for these and/or other functional interactions. The antisera were identified by combined immunogold-silver and immunoperoxidase labeling in single coronal sections through the caudate-putamen nuclei of adult rats. These animals were given intraventricular injections of colchicine, and the brains were fixed by acrolein perfusion prior to immunocytochemical labeling. By light microscopy, perikarya and processes containing enkephalin-like immunoreactivity (ELI) were seen in close proximity to varicose processes immunoreactive for TH. Electron microscopy further demonstrated that the ELI was localized to perikarya, dendrites, and axon terminals, whereas the TH was exclusively in axons and terminals. The dendrites containing ELI were postsynaptic to terminals that were either (1) without detectable immunoreactivity, or (2) immunoreactive for TH or enkephalin. Nonsynaptic portions of the dendrites containing ELI were covered with astrocytic processes or were in direct apposition to unlabeled dendrites. Terminals containing ELI were densely immunoreactive and were in direct contact with (1) unlabeled and occasionally enkephalin-labeled proximal dendrites, and (2) TH-labeled and unlabeled terminals. In comparison with the opiate terminals, most catecholaminergic terminals were lightly immunoreactive for TH and usually contacted more distal unlabeled dendrites or spines and, more rarely, dendrites containing ELI. In a few favorable planes of section, the terminals containing ELI and those containing TH (1) converged on common unlabeled dendrites, or (2) formed dual contacts on two different labeled or unlabeled targets. Junctions formed by terminals containing ELI and TH were sometimes characterized by symmetric synaptic densities. However, numerous other dendritic and all axonal appositions were without recognized membrane densities. The findings of the study provide anatomical substrates for multilevel interactions between catecholamines, mostly dopamine, and enkephalin in rat dorsal striatum. These include (1) monosynaptic input from dopaminergic terminals to neurons containing enkephalin, (2) presynaptic modulation of transmitter release through axonal appositions, and (3) dual regulation of common targets through convergent input. In addition, the findings suggest that both enkephalin and dopamine may have similar modulatory roles in synchronizing the activity of dual targets postsynaptic to individual axon terminals. Alterations in any one of these multiple types of interactions could account for noted motor or sensory symptoms in neurological disorders characterized by depletion of dopamine or endogenous opiate peptides, or both.

Ultrastructure of aberrant serotonin-immunoreactive fibers in the caudate putamen complex of the aged rat.

Degeneration of neurons in the central nervous system is associated with morphological changes. Previous observations made at the light microscopical level indicated degeneration of serotonin-immunoreactive (IR) fibers in the aged rat brain. In this study, a comparison at the ultrastructural level was made between serotonin-IR normal thin and aberrant swollen varicose fibers in the caudate-putamen complex of the aged rat. Ultrastructural features such as the size and content of the thin varicose fibers resembled those in the caudate-putamen complex of the young rat as reported by others. The aberrant profiles were swollen, reaching a size of 6 microns. Their vesicles varied in size and were no longer uniformly round. Moreover, distorted mitochondria and membrane-filled vacuolelike structures were a common feature of the aberrant profiles. These changes are indicative of a degenerative process and give further evidence that, whereas many serotonergic fibers are preserved at high age, other serotonergic fibers are degenerating in the caudate-putamen complex of the aged rat.

The histological effects of intracerebral injection or infusion of MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) and MPP+ (1-methyl-4-phenylpyridinium) in rat and mouse.

Bilateral infusion of MPTP into the substantia nigra, ventral tegmental area or putamen of the rat brain provoked accumulation of leucocytes, but the periphery of nigral lesions showed no significant nerve cell loss. Tyrosine hydroxylase labelling of dopaminergic perikarya showed a normal staining pattern. In contrast, MPP+ was more destructive. After one day there was local degeneration of neuronal and glial elements. After one month there was tissue necrosis and central cavitation, but, like MPTP, there was no evidence of selective nigral cell loss. Striatal injection of MPP+ also failed to produce retrograde nigral damage. It is concluded that the toxicity of MPP+ applied directly to the dopamine system is a consequence of a severe non-selective necrotic lesion.

Regional and subcellular distribution of Thy-1 in human brain assayed by a solid-phase radioimmunoassay.

A solid-phase radioimmunoassay, specific for the monomeric form of human Thy-1, was developed and used for quantitation of the Thy-1 antigen in human brain tissue. Determination of Thy-1 in homogenates of 12 anatomically defined brain regions showed that Thy-1 is present throughout the human brain. However, significant variation was found in the expression of the glycoprotein in different regions. Thy-1 appears to be generally enriched within gray matter: caudate nucleus, cerebral cortex, and putamen were found to contain the highest Thy-1 concentration (approximately 2.5 micrograms Thy-1/mg protein). Interestingly, the cerebellar cortex contained only 25% of the Thy-1 concentration of cerebral gray matter. Cerebral subcortical white matter contained half the amount of Thy-1 compared to cerebral cortex. Determination of Thy-1 in subcellular fractions prepared from human brain biopsy tissue indicated that the highest relative concentration of Thy-1 is associated with synaptosomal membranes and myelin/axonal membrane fractions.

Dopamine and cholecystokinin immunoreactive neurons in mesencephalic grafts reinnervating the neostriatum: evidence for selective growth regulation.

Pieces of embryonic mesencephalic tissue rich in dopamine and cholecystokinin immunoreactive neurones were grafted to the dorsal surface of the caudate-putamen of adult host rats subjected to unilateral dopamine depleting lesions. After 3 months, neuronal survival in the graft and fibre outgrowth into the host brain were studied by tyrosine hydroxylase and cholecystokinin immunohistochemistry, both in serial sections and by elution and restaining of the same sections. Both dopamine- and cholecystokinin-containing neurones as well as neurons containing both compounds survived the transplantation process. The ratio of neurones in which dopamine and cholecystokinin-like immunoreactivity occurred independently and in coexistence was similar in the grafts to that seen in the intact ventral mesencephalon. This suggests that the grafted cells maintain and express at least some of their normal chemical characteristics in the ectopic cortical location. Only those fibres which contained tyrosine hydroxylase but apparently lacked the cholecystokinin-like peptide showed extensive reinnervation of the host neostriatum. The cholecystokinin-positive fibres were found in a narrow zone immediately adjoining the graft. These results indicate that the dopaminergic reinnervation of the denervated neostriatum is preferentially carried out by the population of grafted mesencephalic dopamine neurones apparently lacking the cholecystokinin-like peptide. This suggests the presence of growth regulating mechanisms in the denervated neostriatum which selectively favour the ingrowth of fibres from the appropriate dopaminergic neuronal subset. The transplantation technique may therefore provide a powerful tool for the study of neurone-target interactions in the establishment of neuronal connections, and of the possible role of peptidergic coexistence in the development and organization of monoaminergic pathways and their innervation patterns.