TYK2 signaling promotes the development of autoreactive CD8+ cytotoxic T lymphocytes and type 1 diabetes

Tyrosine kinase 2 (TYK2), a member of the JAK family, has attracted attention as a potential therapeutic target for autoimmune diseases. However, the role of TYK2 in CD8+ T cells and autoimmune type 1 diabetes (T1D) is poorly understood. In this study, we generate Tyk2 gene knockout non-obese diabetes (NOD) mice and demonstrate that the loss of Tyk2 inhibits the development of autoreactive CD8+ T-BET+ cytotoxic T lymphocytes (CTLs) by impairing IL-12 signaling in CD8+ T cells and the CD8+ resident dendritic cell-driven cross-priming of CTLs in the pancreatic lymph node (PLN). Tyk2-deficient CTLs display reduced cytotoxicity. Increased inflammatory responses in β-cells with aging are dampened by Tyk2 deficiency. Furthermore, treatment with BMS-986165, a selective TYK2 inhibitor, inhibits the expansion of T-BET+ CTLs, inflammation in β-cells and the onset of autoimmune T1D in NOD mice. Thus, our study reveals the diverse roles of TYK2 in driving the pathogenesis of T1D.

Subtyping of Type 1 Diabetes as Classified by Anti-GAD Antibody, IgE Levels, and Tyrosine kinase 2 (TYK2) Promoter Variant in the Japanese

Objective

Type 1 diabetes (T1D) is known to be caused by Th1 cell-dependent autoimmunity. Recently, we reported that TYK2 promoter variant serves as a putative virus-induced diabetes susceptibility gene associated with deteriorated interferon-dependent antiviral response. TYK2 is also related to HIES, that is, Th2 cell-dependent. Therefore, TYK2 promoter variant may be also associated with the pathogenesis of T1D, modulating Th1/Th2 balance.

Research Design and Methods

We assessed the association between anti- GAD Ab, IgE levels, and TYK2 promoter variant among 313 T1D patients, 184 T2D patients, and 264 YH controls in the Japanese.

Results

T1D patients had elevated IgE (median, 56.7 U/ml; p < 0.0001) compared with T2D patients (22.5 U/ml) and controls (43.3 U/ml). Contrary to our expectations, there was no correlation between TYK2 promoter variant and IgE levels. We found that T1D could be subtyped as four groups based on anti-GAD Ab and IgE profile: Subtype 1, anti-GAD Ab positive and non-elevated IgE (47.0%); Subtype 2, anti-GAD Ab negative and non-elevated IgE (35.1%); Subtype 3, anti-GAD Ab positive and elevated IgE (10.9%); and Subtype 4, anti-GAD Ab negative and elevated IgE (7.0%). In Subtype 2, a significantly higher incidence was observed in T1D cases carrying the TYK2 promoter variant (OR, 2.60; 95%CI, 1.03–6.97; p = 0.032), and also showing a flu-like syndrome at diabetes onset (OR, 2.34; 95%CI, 1.27–4.35; p = 0.003).

Interpretation

Anti-GAD Ab and IgE profiling helps classifying T1D into four groups that recognize variable pathogenic bases of T1D.

•

T1D can be subtyped into 4 groups based on anti-GAD Ab, IgE levels and TYK2 promoter variant.

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Only one subtype, without anti-GAD Ab or elevated IgE, was associated with TYK2 promoter variant and flu-like syndrome.

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Profiling of T1D by anti-GAD Ab and IgE levels is useful to realize the variable immuno-pathogenesis of T1D.

Since TYK2 gene is associated with T1D and HIES, we assessed the association between anti-GAD Ab, IgE levels, and TYK2 promoter variant in patients with T1D. Consequently, T1D can be subtyped into 4 distinct groups based on these clinical laboratory and genetic markers. Only those patients without anti-GAD Ab or elevated IgE were associated with TYK2 promoter variant and with flu-like syndrome at the diabetes onset, suggestive of association with virus-induced diabetes. This study describes the usefulness of subtyping of T1D with variable immunological bases and provides a clue to delineate the pathogenesis of T1D.

TYK2 Promoter Variant and Diabetes Mellitus in the Japanese

BACKGROUND

Recently, natural mutation of Tyrosine kinase 2 (Tyk2) gene has been shown to determine susceptibility to murine virus-induced diabetes. In addition, a previous human genome-wide study suggested the type 1 diabetes (T1D) susceptibility region to be 19p13, where the human TYK2 gene is located (19p13.2).

METHODS

Polymorphisms of TYK2 gene at the promoter region and exons were studied among 331 healthy controls, and 302 patients with T1D and 314 with type 2 diabetes (T2D) in the Japanese.

FINDINGS

A TYK2 promoter haplotype with multiple genetic polymorphisms, which are in complete linkage disequilibrium, named TYK2 promoter variant, presenting decreased promoter activity, is associated with an increased risk of not only T1D (odds ratio (OR), 2.4; 95% confidence interval (CI), 1.2 to 4.6; P = 0.01), but also T2D (OR, 2.1; 95% CI, 1.1 to 4.1; P = 0.03). The risk is high in patients with T1D associated with flu-like syndrome at diabetes onset and also those without anti-glutamic acid decarboxylase autoantibody.

INTERPRETATION

The TYK2 promoter variant is associated with an overall risk for diabetes, serving a good candidate as a virus-induced diabetes susceptibility gene in humans.

FUNDING

Ministry of Education, Culture, Sports, Science and Technology and of Health, Labor and Welfare of Japan.

Reduced Tyk2 gene expression in β-cells due to natural mutation determines susceptibility to virus-induced diabetes

Accumulating evidence suggests that viruses play an important role in the development of diabetes. Although the diabetogenic encephalomyocarditis strain D virus induces diabetes in restricted lines of inbred mice, the susceptibility genes to virus-induced diabetes have not been identified. We report here that novel Tyrosine kinase 2 (Tyk2) gene mutations are present in virus-induced diabetes-sensitive SJL and SWR mice. Mice carrying the mutant Tyk2 gene on the virus-resistant C57BL/6 background are highly sensitive to virus-induced diabetes. Tyk2 gene expression is strongly reduced in Tyk2-mutant mice, associated with low Tyk2 promoter activity, and leads to decreased expression of interferon-inducible genes, resulting in significantly compromised antiviral response. Tyk2-mutant pancreatic β-cells are unresponsive even to high dose of Type I interferon. Reversal of virus-induced diabetes could be achieved by β-cell-specific Tyk2 gene expression. Thus, reduced Tyk2 gene expression in pancreatic β-cells due to natural mutation is responsible for susceptibility to virus-induced diabetes.

Diabetes can be caused by viral infections in humans and some inbred mice, suggesting genetic predisposition. Here the authors show that mutations in Tyk2 gene underlie susceptibility to virus-induced diabetes in mice, due to Tyk2 requirement for antiviral response in insulin-producing cells.

Regulation of human autoimmune regulator (AIRE) gene translation by miR-220b

Although mutations of autoimmune regulator (AIRE) gene are responsible for autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), presenting a wide spectrum of many characteristic and non-characteristic clinical features, some patients lack AIRE gene mutations. Therefore, something other than a mutation, such as dysregulation of AIRE gene, may be a causal factor for APECED or its related diseases. However, regulatory mechanisms for AIRE gene expression and/or translation have still remained elusive. We found that IL-2-stimulated CD4(+) T (IL-2T) cells showed a high expression of AIRE gene, but very low AIRE protein production, while Epstein-Barr virus-transformed B (EBV-B) cells express both AIRE gene and AIRE protein. By using microarray analysis, we could identify miR-220b as a possible regulatory mechanism for AIRE gene translation in IL-2T cells. Here we report that miR-220b significantly reduced the expression of AIRE protein in AIRE gene with 3'UTR region transfected 293T cells, whereas no alteration of AIRE protein production was observed in the open reading frame of AIRE gene alone transfected cells. In addition, anti-miR-220b reversed the inhibitory function of miR-220b for the expression of AIRE protein in AIRE gene with 3'UTR region transfected cells. Moreover, when AIRE gene transfected cells with mutated 3'UTR were transfected with miR-220b, no reduction of AIRE protein production was observed. Taken together, it was concluded that miR-220b inhibited the AIRE gene translation through the 3'UTR region of AIRE gene, indicating that miR-220b could serve as a regulator for human AIRE gene translation.

Autoimmune gastro-pancreatitis with anti-protein disulfide isomerase-associated 2 autoantibody in Aire-deficient BALB/cAnN mice

Although the autoimmune regulator (Aire) knockout (KO) mouse model has been reported to present various organ-specific autoimmune diseases depending on genetic background, autoimmune pancreatitis in mice of BALB/c background has not yet been reported. Here, we report that Aire KO mice with BALB/cAnN background showed significant lymphoid cell infiltration in the pancreas and stomach. To examine whether the phenotype in the pancreas and stomach is due to autoimmune reaction associated with autoantibody production, indirect immunofluorescence staining followed by Western blot analysis was performed. Consequently, the autoantibody against pancreas and stomach was detected in the sera of Aire KO mice, and the target antigen of the autoantibody was identified as protein disulfide isomerase-associated 2 (Pdia2), which was reported to be expressed preferentially in the pancreas and stomach. Thus, Aire KO mice of BALB/cAnN background can serve as a useful animal model for autoimmune gastro-pancreatitis with anti-Pdia2 autoantibody production.

The role of TNFα pathway and microRNA in regulating autoimmune regulator gene expression and translation (P4101)

Autoimmune regulator (AIRE) is a responsible gene for autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), presenting multiple autoimmune diseases. AIRE gene is expressed in the thymus and lymph nodes. Thus, AIRE gene plays an important role in both the central and peripheral regulation of immune responses. However, there are some patients with APECED, who lack mutations in AIRE gene. Therefore, dysfunction of the regulatory mechanism of AIRE gene may be associated with the pathogenesis of APECED. In this study, we found that nuclear factor-κB (NF-κB) pathway regulated AIRE gene expression during maturation process of dendritic cells under TNFα stimulation, along with the significant elevation of AIRE gene expression. By inhibiting NF-κB pathway, AIRE gene expression was decreased. We also found that miR-220b inhibited the translation of AIRE gene, binding 3’ untranslated region (3’UTR) of the target mRNA. AIRE protein expression was inhibited by overexpressing microRNAs in 293T cells transfected with AIRE gene which have 3’UTR plasmid but not in AIRE open reading frame (ORF) alone. At least, miR-220b was not expressed in the normal thymus which expresses high level of both AIRE gene and AIRE protein, to delete autoreactive T cells. Thus, it was concluded that there are multiple the regulatory mechanisms of AIRE gene expression, and deterioration of those mechanisms may be associated with APECED phenotype.

The significance of tyrosine kinase 2 gene in encephalomyocarditis-D virus-induced diabetes as studied in Tyk2 gene knockout mice (P6334)

Type 1 diabetes mellitus results form progressive loss of pancreatic β cells. The virus, as one of environmental factors, has been long considered to play a role in the development of type 1 diabetes. The D variant of encephalomyocarditis (EMC-D) virus induced susceptible strain of mice to become type 1 diabetes. We have already reported that innate immunity may play an important role in protection against EMC-D virus-induced diabetes (Arch Virol, 2008). In the present study, we analyzed the role of Tyk2 gene in the pathogenic mechanism of EMC-D virus-induced diabetes by using Tyk2 gene knockout (KO) mice. Tyk2 gene KO C57BL/6J mice, mouse strain resistant to EMC-D virus-induced diabetes, developed diabetes. In order to examine whether Tyk2 gene expression was important in parenchymal or immune cells to protect against EMC-D virus-induced diabetes, we developed splenic chimera mice. Tyk2 gene expression was important in parenchymal cells, but not in spleen cells, to resist against EMC-D virus-induced diabetes. Consistently, mice specifically expressed Tyk2 gene only in pancreatic β cells prevented EMC-D virus-induced diabetes. These observations suggest that Tyk2 gene expressed in pancreatic β cells plays a significant role in preventing EMC-D virus-induced diabetes in mice.

Total deletion and a missense mutation of ITPR1 in Japanese SCA15 families

BACKGROUND

Spinocerebellar ataxia type 15 (SCA15) is a progressive neurodegenerative disorder characterized by pure cerebellar ataxia, very slow progression, and distinct cerebellar atrophy. The locus for SCA15 was first mapped to 3p24.2-3pter in an Australian family. We have subsequently mapped two Japanese families presenting with ataxia and postural tremor of the head, arm, or trunk to the SCA15 locus. Recently, partial deletions involving both the type 1 inositol 1,4,5-triphosphate receptor (ITPR1) and sulfatase modifying factor 1 (SUMF1) genes have been identified in Australian and British families with SCA15.

METHODS

We conducted fine haplotype analysis on the region including ITPR1. To identify the deletion, we conducted gene dosage analysis and array-based comparative genomic hybridization (aCGH) analysis. Gene expression analysis was performed using quantitative real-time reverse transcription PCR. Mutational analyses of ITPR1 and SUMF1 were also performed.

RESULTS

We have identified a 414-kb deletion including the entire ITPR1 and exon 1 of SUMF1 in patients in family A. The expression levels of ITPR1 and SUMF1 mRNAs of the patient were half those of the normal control. Furthermore, in family B, we have identified a C-to-T substitution at position 8581 of ITPR1, resulting in the amino acid substitution of leucine for proline at codon 1059, which is highly conserved among species.

CONCLUSIONS

Our results strongly confirm that ITPR1 is the causative gene for SCA15 and suggest that we need to investigate the point mutation in ITPR1 in the patients with autosomal dominant cerebellar ataxia and tremor.

The significance of T cells, B cells, antibodies and macrophages against encephalomyocarditis (EMC)-D virus-induced diabetes in mice

In order to clarify the significance of protective mechanisms against encephalomyocarditis (EMC) virus-induced diabetes in mice, we studied the relative importance of T cells, B cells, antibodies and macrophages in the prevention of virus-induced diabetes. Neither T cell-deficient athymic nude mice nor B cell-deficient microMT/microMT mice showed an enhanced clinical course of EMC-D virus-induced diabetes, indicating that neither T cells nor B cells played a major role in the protection against EMC-D-virus-induced diabetes. Transfer of a large amount of antiserum to EMC-D-virus-infected mice protected the development of diabetes only when transferred within 36 h of infection, the timing of which was earlier than that for the production of natural neutralizing antibodied. Since pretreatment of mice with the macrophage-activating immunopotentiator Corynebacterium parvum (CP) completely prevented the development of diabetes, we studied the clinical outcome of EMC-D-virus-infected mice pretreated with CP. Mice treated with CP showed reduced proliferation of EMC-D virus in the affected organs, including the pancreas, while the levels of development of neutralizing antibody and serum interferon were not enhanced compared with the controls. Finally, we studied the macrophages derived from mice pretreated with CP and found that they inhibited the growth of EMC-D virus in vitro more than those derived from non-treated and thioglycolate-treated mice. Taken together, it can be suggested that neither T cells nor B cells, which have to do with adaptive immunity, play a significant role in the pathogenesis of EMC-D-virus-induced diabetes, while innate immunity, which is dependent on activated macrophages, contributes to in vivo resistance against EMC-D-virus-induced diabetes.

Recurrent herpes simplex virus infection in a patient with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy associated with L29P and IVS9-1G>C compound heterozygous autoimmune regulator gene mutations

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) has characteristic clinical features with organ-specific autoimmune polyendocrine diseases and candidiasis, caused by the mutations of autoimmune regulator (AIRE) gene. Although almost all patients are complicated with mucocutaneous candidiasis, no apparent susceptibility to other infections has yet been reported. We herein report that a patient with APECED suffered from recurrent herpes simplex virus type 1 (HSV-1) infection after severe primary herpetic stomatitis, associated with sequential HSV-1 isolates of the same genomic profile, consistent with endogeneous recurrence. Thus, not only candidiasis but also HSV infection should receive more attention in patients with APECED, with treatment being administered accordingly.

The C-terminal Tail of Mitochondrial Transcription Factor A Markedly Strengthens its General Binding to DNA

Mitochondrial transcription factor A (TFAM) contains a basic C-terminal tail which is essential for the promoter-specific transcription. TFAM is also a major component of a protein-mitochondrial DNA (mtDNA) complex, called nucleoid, as a non-specific DNA-binding protein. However, little is known about a role of the C-tail in the nucleoid. Overexpression of full-length TFAM decreased the amount of a D-loop form of mtDNA in cells, while overexpression of TFAM lacking its C-tail (TFAM-DeltaC) did not, suggesting that the C-tail is involved in destabilization or formation of the D-loop. An mRNA for mtDNA-derived ND1 was hardly decreased in the former but rather decreased in the latter. Given that the D-loop formation is coupled with the transcription, the decrease in the D-loop is likely due to its destabilization. The recombinant full-length TFAM much strongly unwound DNA than TFAM-DeltaC, which is consistent with the above idea because D-loop is resolved by unwinding of the supercoiling state. Notably, truncation of the C-tail decreased DNA-binding activity of TFAM by three orders of magnitude. Thus, the C-terminal tail of TFAM is important for the strong general binding to mtDNA. This strong DNA-binding conferred by the C-tail may play an important role in the nucleoid structure.

Autoimmune regulator (AIRE) gene is expressed in human activated CD4+ T-cells and regulated by mitogen-activated protein kinase pathway

The autoimmune regulator (AIRE) gene is a gene responsible for autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy. Here we show that AIRE is expressed in human peripheral CD4-positive T-cells, and most highly in antigen-and interleukin 2-stimulated T (IL-2T) cells. Mitogen-activated protein kinases (MAPKs), including MAPK kinase (MEK) 1/2 and p38 MAPK, were phosphorylated in IL-2T cells and the expression of the AIRE gene was inhibited by a specific p38 MAPK inhibitor (SB203580), thereby indicating that AIRE gene expression is controlled by the MAPK pathway in IL-2T cells. These data suggested the possible significance of the AIRE gene in the peripheral immune system.

Japanese SCA families with an unusual phenotype linked to a locus overlapping with SCA15 locus

The authors identified two Japanese spinocerebellar ataxia (SCA) families characterized by postural and action tremor and a very slow progression rate. A genome-wide linkage analysis revealed linkage to chromosome 3p26.1-25.3 with the highest multipoint lod score at D3S3728 (Zmax = 3.31 at theta = 0.00). The candidate region was 14.7 cM flanked by D3S1620 and D3S3691, which was partly overlapping with the locus of SCA15 characterized by pure cerebellar ataxia. Despite the difference in phenotypes, there remains a possibility that the causative gene for these Japanese SCA is allelic to SCA15.

Pressure-induced superconductor-insulator transition in the spinel compound CuRh2S4

We performed resistivity measurements in CuRh2S4 under quasihydrostatic pressure of up to 8.0 GPa, and found a pressure-induced superconductor-insulator transition. Initially, with increasing pressure, the superconducting transition temperature T(c) increases from 4.7 K at ambient pressure to 6.4 K at 4.0 GPa, but decreases at higher pressures. With further compression, superconductivity in CuRh2S4 disappears abruptly at a critical pressure P(SI) between 5.0 and 5.6 GPa, when it becomes an insulator.

Decrease of neurons in the medullary arcuate nucleus in myotonic dystrophy

Respiratory insufficiency has been reported frequently in patients with myotonic dystrophy (MyD). Recent data support the hypothesis that this respiratory failure results from a primary dysfunction of the central nervous system. The medullary arcuate nucleus (ARC) has been shown to be involved in the regulation of respiration. We performed a quantitative study of neurons in the ARC in eight MyD patients, ten control subjects with other neurological diseases (control group A) and eight control subjects without neurological diseases (control group B). Alveolar hypoventilation of the central type occurred in three of the MyD patients but not in the remaining MyD patients or controls. The density of neurons in the ARC in MyD patients with hypoventilation was significantly lower than in MyD patients without hypoventilation and control groups A and B. There was no significant difference in the neuronal density of the ARC between MyD patients without hypoventilation and control groups A and B. These data suggest that the neuronal loss of the ARC is associated with the presence of hypoventilation in MyD.

[Central nervous system tuberculosis with and without HIV infection--clinical, neuroimaging, and neuropathological study]

Clinical data, neuroimaging, and neuropathology of 17 patients with central nervous system tuberculosis were reported. Of this population, 12 were men, 5, women; ages ranged from 23 to 75 years (mean, 46.9). There were three HIV positive patients among them. More than a half of patients had disturbance of consciousness as initial symptom. Neurological signs were variable such as visual acuity loss, hemiparesis, paraparesis, cerebellar ataxia, and tremor, though disturbance of consciousness was the most frequent (36%). Neuroimaging (X-ray CT and MRI) revealed meningeal enhancement (53%), tuberculoma (50%), hydrocephalus, infarction or bleeding and spinal cord tuberculoma. There were three patients who showed paradoxical progression. Eleven patients were performed CSF examination, all of them revealed increased cell count (mean, 206 counts/mm3) and protein (mean, 225 mg/dl), but only 4 patients were positive on bacteriological examination including PCR. Seven patients died and 5 patients were performed autopsy. Neuropathologically, all patients showed a stage of meningitis prominent on basal brain (basal cistern and/or Sylvian fissure). Cell infiltrations including lymphocyte, monocyte, and eosinocyte were most severe around blood vessels, and observed in all cases except one which showed only fibroblast and collagen fibers indicating healed stage. In some cases, there existed epithelioid cells and Langhans giant cells, and in some cases, fibrin exudate. There were three cases having tuberculoma, one HIV case and two non-HIV cases. Center of tuberculoma in non-HIV case was formed by caseous necrosis, and tuberculoma was surrounded by granuloma constituted by epithelioid cells and Langhans giant cells with lymphocyte cell infiltration and proliferation of blood vessels. In contrast, tuberculoma of HIV case did not include granuloma, and was formed with small cells with large nucleus which surrounded arteries. Our studies, as other studies, failed to show any differences between HIV and non-HIV patients clinically, as well as on neuroimaging study. But neuropathological study suggests that mechanism of tuberculoma formation may be different between in HIV positive patients and in non-HIV patients.

Abnormal dentatorubral-pallidoluysian atrophy (DRPLA) protein complex is pathologically ubiquitinated in DRPLA brains

Dentatorubral-pallidoluysian atrophy (DRPLA) is caused by expansion of a glutamine repeat in DRPLA protein. DRPLA protein undergoes greater complex formation in DRPLA brain tissue, and expanded glutamine repeat enhances complex formation of DRPLA protein. Immunoblots with and without reduction show that the DRPLA protein complex is ubiquitinated only in DRPLA brain tissue. Moreover, immunoblots of regional DRPLA brain tissues reveal that pathological ubiquitination of DRPLA protein complex is found selectively in affected lesions. Double-labeling immunohistochemical studies with antibodies against DRPLA protein and ubiquitin demonstrate that the DRPLA protein is co-localized with ubiquitin in DRPLA neurons and show characteristic neuronal cytoplasmic inclusions with ubiquitinated DRPLA protein complex in the center. Our findings suggest that DRPLA protein undergoes abnormal complex formation with expanded glutamine repeat, and then the complex is pathologically ubiquitinated in DRPLA brain tissue. Pathological ubiquitination of abnormal DRPLA protein complex plays a role in DRPLA pathology.

[Prognosis of multiple system atrophy--survival time with or without tracheostomy]

Prognosis of 21 patients with multiple system atrophy (MSA) who deceased or received tracheostomy is described. The percentage of patients with MSA among the cases of spinocerebellar degeneration was 40% in National Tokyo Hospital. There were 12 women and 9 men, and the mean age at onset was 56 years. Seventy-four percent of MSA patients was olivopontocerebellar atrophy (OPCA), 22% was striatonigral degeneration (SND). The mean age of 17 deceased patients (10 women, and 7 men) was 65.5 years. Ten patients did not undergo tracheostomy and deceased, and 11 patients underwent tracheostomy, among whom 4 patients are still alive. Mean duration of illness from onset to death (without tracheostomy) or tracheostomy was 6.8 years. Cause of death of patients who did not undergo tracheostomy was related to paresis of the larynx or pharynx, for example, aspiration pneumonia due to dysphagia, vocal cord paralysis and sudden death. Some of those who underwent tracheostomy deceased for causes which were not directly related to MSA such as cerebral hemorrhage or uremia, but others seem to be related to some problems of respiratory center such as central chronic respiratory failure, or sudden death (sometimes it happened after infection, but the obstruction of the respiratory tract was not always present at autopsy).

Loss of catecholaminergic neurons in the medullary reticular formation in myotonic dystrophy

OBJECTIVE

To clarify the possible relation between the extent of involvement of catecholaminergic neurons and the presence of alveolar hypoventilation in patients with myotonic dystrophy (MyD).

BACKGROUND

Respiratory insufficiency has been reported frequently in MyD patients. Recent data support the hypothesis that this respiratory failure results from a primary dysfunction of the CNS.

METHODS

The authors performed a quantitative immunoreactive study of tyrosine hydroxylase immunoreactive (TH+) neurons linked to hypoventilation in the dorsal central medullary nucleus (DCMN), the ventral central medullary nucleus (VCMN), and the subtrigeminal medullary nucleus (SMN)--where the autonomic respiratory center is thought to be located--in eight MyD patients and in 10 age-matched control subjects. Alveolar hypoventilation of the central type was present in three of the MyD patients but not in the remaining MyD patients or the control subjects.

RESULTS

The densities of TH+ neurons of the DCMN, the VCMN, and the SMN in MyD patients with hypoventilation were significantly lower than in those without hypoventilation (p < 0.02, p < 0.01, and p < 0.01, respectively) and control subjects (p < 0.01, p < 0.01, and p < 0.01, respectively).

CONCLUSIONS

These data suggest that the loss of TH+ neurons of the DCMN, the VCMN, and the SMN is associated with the presence of hypoventilation in MyD and may be an important feature of MyD.

Reversible memory disturbance and intelligence impairment induced by long-term anticholinergic therapy

It is controversial whether long-term anticholinergic therapy (AC-T) can cause short-term memory disturbance, long-term memory disturbance or intelligence impairment. Ninety patients with Parkinson's disease were examined prospectively to clarify the existence of memory and intelligence impairment induced by long-term AC-T. Neuropsychological tests detected eight patients with at least one of four types of deficits; intelligence impairment in four patients, verbal delayed recall impairment in eight, verbal short-term memory disturbance in five, and verbal long-term memory disturbance in six. Two types of verbal memory disturbance (short-term one and long-term one) appeared with double dissociation, suggesting that there may be an independence between the two types of verbal memory system. Older patients were more prone to suffer from these reversible deficits. Moreover, all of the patients who resumed AC-T, showed recurrence of the deficits acutely. These observations should indicate the tight relation between long-term AC-T and neuropsychological deficits.

Loss of serotonin-containing neurons in the raphe of patients with myotonic dystrophy: a quantitative immunohistochemical study and relation to hypersomnia

Hypersomnia occurs frequently in patients with myotonic dystrophy (MyD). We performed a quantitative immunohistochemical study of serotonin (5-HT)-containing neurons linked to hypersomnia in the dorsal raphe nucleus (DRN) and the superior central nucleus (SCN) in 8 patients with MyD, 5 of whom showed hypersomnia, and in 12 age-matched controls. The densities of 5-HT neurons in the DRN and the SCN were significantly lower in MyD patients with hypersomnia than in MyD patients without hypersomnia and controls. These data suggest that the loss of 5-HT neurons of the DRN and the SCN is associated with the presence of hypersomnia in MyD.

Intracytoplasmic inclusion bodies of the substantia nigra in myotonic dystrophy. Immunohistochemical observations

We recently reported a significantly higher incidence of intracytoplasmic inclusion bodies (IIBs) of the substantia nigra in patients with myotonic dystrophy (MyD) than in age-matched controls. The changes are, per se, not specific, since a small percentage of disease and normal controls also showed similar inclusions. To elucidate the pathological significance of the inclusion in MyD, we studied immunohistochemical characteristics of IIBs of the substantia nigra in eight patients with MyD. Many IIBs showed moderately intense immunoreactivity for ubiquitin, microtubule-associated protein (MAP) 1 and MAP 2. However, the IIBs did not react with any of the following: anti-neurofilament protein antibodies (Abs) (68, 160 and 200 kDa), anti-neuron-specific enolase antibody (Ab), anti-tau Ab, anti-tubulin Abs (alpha and beta), anti-paired helical filament Ab, anti-actin Ab, anti-phosphorylated epitope of neurofilaments Ab, anti-synaptophysin Ab, anti-myelin basic protein Ab, anti-actin Ab and anti-glial fibrillary acidic protein Ab. Our results suggest that IIBs of the substantia nigra in MyD are related to an alteration of neuronal cytoskeleton metabolism affecting microtubular proteins in conjunction with activation of ubiquitin proteolytic systems.

Brain regional differences in the expansion of a CAG repeat in the spinocerebellar ataxias: dentatorubral-pallidoluysian atrophy, Machado-Joseph disease, and spinocerebellar ataxia type 1

Three autosomal dominant spinocerebellar ataxias, dentatorubral-pallidoluysian atrophy (DRPLA), Machado-Joseph disease (MJD), and spinocerebellar ataxia type 1 (SCA1), are associated with the expansion of a CAG repeat in the respective genes. To investigate the association between CAG repeat expansion and neuropathological findings, we analyzed several brain regions from 9 cases of DRPLA, 3 cases of MJD, and 1 case of SCA1. We found that the expanded alleles were smaller in the cerebellar cortex than in other brain regions, such as the frontal cortex, in these three diseases. The discrepancy in the expanded CAG repeat length between cerebellar cortex and other tissues was most prominent in DRPLA, and especially in cases of adult-onset DRPLA. A significant correlation was found between the age at onset of DRPLA and the size of the CAG repeat expansion. Cerebella of DRPLA patients were microscopically dissected into three layers, the molecular and granular layers and the white matter, which were analyzed separately. The lower level of CAG repeat expansion in DRPLA cerebella was representative of CAG repeat expansion in the granule cells. The microdissected samples of the granular layer of the hippocampal formation, which is densely packed with neuronal cells, revealed that the degree of CAG repeat expansion in this layer was similar to that in the cerebellum. These observations suggest that granule cells in the cerebellum and hippocampus have low levels of CAG repeat expansion, and that other types of cells exhibit a higher level of CAG repeat expansion, in spinocerebellar ataxias.

Expression of dentatorubral-pallidoluysian atrophy (DRPLA) proteins in patients

The genetic defect dentatorubral-pallidoluysian atrophy (DRPLA) is caused by expansion of a CAG trinucleotide repeat. The mutant gene is translated into protein whose electrophoretic mobility correlates to the number of expanded CAG trinucleotide repeats, indicating that the protein carries an expanded glutamine repeat. Using two polyclonal antibodies raised against the DRPLA gene product in immunoblotting, we determined the untruncated DRPLA proteins, and showed that the amounts of mutant and wild-type DRPLA proteins were similar in DRPLA brain tissues and lymphoblastoid cells, suggesting that regulation of the level of translation of the DRPLA gene is not central to the development of the disease.

Immunohistochemical study of intracytoplasmic inclusion bodies of the thalamus in myotonic dystrophy

Intracytoplasmic inclusion bodies of the thalamus in eight patients with myotonic dystrophy (MyD) were studied immunohistochemically. The intracytoplasmic inclusion bodies of the thalamus (thalamic inclusions, TIs) were strongly immunostained with anti-ubiquitin antibody (Ab) and some of them were mildly stained with anti-microtubule associated protein 1 (MAP 1) and anti-MAP 2 antibodies. However, TIs did not react with any of the following: anti-neurofilament protein Ab, anti-tau Ab, anti-paired helical filament Ab, anti-tubulin Abs (alpha and beta), anti-neuron-specific enolase Ab, anti-glial fibrillary acidic protein Ab, anti-synaptophysin Ab, anti-myelin basic protein Ab, anti-actin Ab and anti-phosphorylated epitope of neurofilaments Ab. Thus, our study demonstrates the unique immunohistochemistry of TIs in MyD which differentiates them from other intracytoplasmic inclusions in various neurodegenerative disorders.

Neuronal loss in the medullary reticular formation in myotonic dystrophy: a clinicopathological study

Respiratory insufficiency occurs frequently in patients with myotonic dystrophy (MyD). We have performed a quantitative study of neurons linked to respiratory function in the dorsal central medullary nucleus (DCMN), the ventral central medullary nucleus (VCMN), and the subtrigeminal medullary nucleus (SMN) in seven patients with MyD and eight age-matched controls. Alveolar hypoventilation of the central type occurred in three of the MyD patients but not in the remaining MyD patients or controls. The densities of neurons of the DCMN, the VCMN, and the SMN in MyD patients with hypoventilation were significantly lower than in MyD without hypoventilation and controls. These data suggest the neuronal loss of the DCMN, VCMN, and SMN is associated with the presence of hypoventilation in MyD and may be an important feature of MyD.

A new familial disorder presenting with amyotrophic lateral sclerosis-like manifestation: a clinicopathological study

We studied a family in which three siblings had an identical clinical feature indistinguishable from familial amyotrophic lateral sclerosis (ALS), consisting of progressive generalized neurogenic muscular atrophy with hyporeflexia and normal sensations beginning in the fourth decade. The duration of illness was about 4 years in all affected members. Autopsy of one patient revealed multiple foci of spongy degeneration in the white matter of the spinal cord, brain stem, cerebellum, and the thalamus, characterized by vacuoles of various size, foamy macrophages and degenerating swollen axons. These changes were most marked in the spinal cord, where there was neither pyramidal tract involvement nor neuronal loss in the anterior horn. The pathological findings were different from those of ALS. A similar disease affected the siblings' mother, suggesting an autosomal dominant inheritance. The disease in the kindred, therefore, appears to be a unique hereditary disorder.

Myotonic dystrophy with alveolar hypoventilation and hypersomnia: a clinicopathological study

We present a case of myotonic dystrophy accompanied by alveolar hypoventilation and hypersomnia. Case history, pulmonary function tests, polygraphic recording, and multiple sleep latency test, concomitant with a restrictive ventilatory abnormality, suggested a central origin of alveolar hypoventilation and hypersomnia in our case. The most significant neuropathological findings were in the tegmentum of the brain stem. Severe neuronal loss and gliosis were observed in the midbrain and pontine raphe, particularly in dorsal raphe nucleus and superior central nucleus. Pontine and medullary reticular formation also showed a marked cell loss and fibrillary gliosis. The alveolar hypoventilation and the hypersomnia in our case may be attributed to these morphological abnormalities, and would appear to be central in nature.

Neuronal cell loss in the dorsal raphe nucleus and the superior central nucleus in myotonic dystrophy: a clinicopathological correlation

A quantitative study of neurons in the dorsal raphe nucleus (DRN) and the superior central nucleus (SCN) was performed in seven patients with myotonic dystrophy (MyD), five of whom showed hypersomnia, and in eight age-matched controls. The densities of neurons in the DRN and the SCN were significantly lower in MyD patients with hypersomnia than in MyD patients without hypersomnia and control subjects. There was an appreciable positive correlation in the density of neurons between the DRN and the SCN in all MyD patients. These data suggest that the neuronal loss of the DRN and the SCN is associated with the presence of hypersomnia in MyD.

[A case of multiple system atrophy presenting a regular involuntary movement of the neck muscles synchronous with respiration]

A patient with multiple system atrophy developed a regular, rhythmic involuntary movement of the neck muscles which appeared synchronous with respiration and could be described as "rocking-of-the-head". He had been treated with antiparkinsonian drugs such as L-dopa, L-dopa/carbidopa, amantadine hydrochloride and trihexiphenidyl hydrochloride for approximately one year. A fluoroscopic study assured that the involuntary "rocking-of-the-head" movement synchronized with the diaphragmatic up-and-down movement. A polygraphic study showed that the accelerometer curve which reflected the rocking movement of the head oscillated at approximately 0.7 Hz and synchronized with the surface EMG discharges of the right sternocleidomastoid muscle and the nasal flow curve. This involuntary movement was seen almost all day long as well as asleep but severest usually in the afternoon. Discontinuation of trihexiphenidyl hydrochloride alone made the involuntary movement less severe but never suppressed it completely. Resumption of the drug made the involuntary movement as severe as it had been. Discontinuation of L-dopa, L-dopa/carbidopa and amantadine hydrochloride was followed by disappearance of the involuntary movement in a day or so, in spite of continued intake of trihexiphenidyl hydrochloride. Rigidity and bradykinesia induced by discontinuation of these drugs, however, made it necessary to resume them. As a result the involuntary movement again exacerbated.

[A case of rabbit syndrome--its unique pharmacological feature]

A 61-year-old woman developed cerebellar ataxia as an initial symptom when she was 52 years old. Her neurological symptom was gradually followed by autonomic nervous system disturbance, pyramidal sign, and rigidity. She was diagnosed as suffering from multiple system atrophy (MSA), when she was 53 years old. Magnetic resonance imaging revealed atrophy of the cerebellum and brainstem. She was accompanied by rabbit syndrome (RS), when she was 61 years old. She had not been given any neuroleptics, which might produce RS, before she developed RS. Her regular involuntary movement was localized in lips, and its frequency was about 3 Hz. While sleeping, she did not have the involuntary movement. We had a chance to conduct pharmacological examination on RS. The administration of atropine or trihexyphenidyl did not change her symptom of RS, and the intravenous injection of levodopa deteriorated the movement. Haloperidol, sulpiride, or chlorpromazine was significantly effective on her involuntary movement of RS. These results indicated that our patient had the supersensitivity in her dopamine receptor. Such supersensitivity might result from the denervation in MSA, because she had not been administered any neuroleptics. RS is generally considered to be a kind of extrapyramidal sign, and we have not been aware of any report about RS, which levodopa deteriorated and neuroleptics improved. The mechanism of her symptom is discussed.

Carcinomatous neuropathy associated with hepatic cell carcinoma: an autopsy case report

A 76-yr-old male patient with carcinomatous neuropathy associated with hepatic cell carcinoma, whose initial symptom was deep sensory disturbance followed by muscle weakness is described. The onset was subacute, followed by slow progression. Sural nerve biopsy, as well as electrophysiological examinations, revealed severe axonal degeneration without any evidence of demyelination. The autopsy findings were similar to findings described in the literature on carcinomatous neuropathy. Although carcinomatous neuropathy is usually associated with lung cancer, this report describes an association with hepatic cell carcinoma. The patient also had motor nerve involvement with positive serum anti-GM1 ganglioside antibody which decreased after immunosuppressant therapy in parallel with recovery of muscle weakness. The anti-GM1 ganglioside antibody may be involved in the pathogenesis of motor disturbance in the present case.

[Natural type interferon-alpha (Namalwa) therapy for multiple myeloma complicated by hemolytic anemia]

A 45-year-old woman with Bence-Jones type multiple myeloma was treated with natural type alpha-interferon (Namalwa interferon), 3 million IU every other day subcutaneously. After about 5 months, she developed hemolytic anemia. However, screening tests for autoantibodies, including direct and indirect antiglobulin (Coombs' tests), were negative. This report is the first case in which hemolytic anemia appeared to be caused by natural type alpha-interferon. It is likely that interferons will be used in treating increasing numbers of patients and that more patients will develop this complication.

[Isospora belli infection in a patient with adult T-cell leukemia]

An adult T cell leukemia (ATL) accompanied with Isospora belli infection was described. A 65-year-old male was admitted to our hospital because of a two month history of watery diarrhea. On admission, physical examination showed slight pallor but no detectable superficial lymphadenopathies. Hepatosplenomegaly was not observed. Laboratory examination revealed a leukocyte count 5,500/microliters with 10% abnormal lymphoid cells. A majority of the abnormal lymphoid cells expressed both CD 4 and CD 8 antigens. The patient was diagnosed as chronic ATL, since anti-HTLV-1 antibody in his serum and monoclonal integration of HTLV-1 proviral DNA in his peripheral mononuclear cells were detected. Isospora belli was found in his feces thereafter, and trimethoprim/sulfamethoxazole was effective for diarrhea. In Japan, there have been only 9 reported cases of lymphoproliferative disorders (including five ATL patients) accompanied with Isospora belli infection. From the descriptions in those reports, these 9 cases might all be ATL patients.

Japanese crossed Wernicke's aphasia

A right-handed Japanese man with no personal or family history of left-handedness developed severe Wernicke's aphasia, a mild constructional disorder, and slight left hemiparesis. MRI revealed infarction in the territory of the righ middle cerebral artery, including areas homologous to Broca's and Wernicke's areas. The cerebral blood flow in these areas remained diminished even after language activation. The most likely explanation is that language production occurred in the left Broca's area, while language comprehension occurred in the right Wernicke's area (a dissociated aphasia).

[Chronic dementia in Parkinson disease treated by long-term administration of anticholinergic drug--evaluation of neuropsychological test, PET, and SPECT]

It is known that the anticholinergic drug causes acute psychosis and memory disturbance, which may be due to cholinergic dysfunction. But it has not been well described that the anticholinergic drug causes chronic dementia after long administration. We describe six cases of chronic dementia, which is thought to be induced by anticholinergic drug. We conducted detailed neuropsychological and neuroradiological examination in these six cases. All of them were Parkinson's disease, and had used anticholinergic drug for more than six months without any side effect, and then their initial symptom of dementia appeared, followed by chronic dementia. All cases recovered reversibly from dementia within a few weeks after stoppage of taking anticholinergic drug. And any of our cases had no possibility in the cause of chronic dementia other than the side effect of anticholinergic drug. Detailed neuropsychological examinations (WAIS, WMSR, and so on) were conducted in all cases, SPECT was in two cases, and PET was in one case, before and after stoppage of the anticholinergic drug. And in all cases, brain MRI was conducted. The indices of attention, verbal memory, visual memory, and delayed recall were significantly elevated after stoppage of drug. And both verbal IQ and performance IQ were increased after stoppage of drug, too. SPECT and PET revealed significant improvement, which showed diffuse and generalized change, not localized change.

["AB-Triple V" therapy of relapsed or refractory acute myelogenous leukemia]

Sixteen adults with acute myelogenous leukemia (AML) in relapse or refractory to conventional therapy were treated with AB-Triple V therapy. This regimen consists of aclarubicin, behenoyl cytosine arabinoside, etoposide, vincristine, and vinblastine or vindesine. Patients who obtained complete remission (CR) were then given monthly three courses of AB-Triple V therapy, and further courses of AB-triple V therapy every three months. Eleven of the 16 patients entered CR, three were no response, and two died early after initial AB-Triple V therapy. Among 11 patients who achieved CR, 7 are alive and in CR during 1 to 13 months, one died of hepatic failure, and three patients died of infection in CR. Systemic arthralgia following the administration of vinblastine were frequently observed. These results indicate that this salvage therapy are useful relapsed or refractory AML. Therefore, the role of this combination chemotherapy as a part of the initial post-remission therapy needs to be evaluated.

An unusual neurological disorder with abnormal copper metabolism

Twin males aged 24 years showed dementia, dysarthria, gait disturbances and involuntary movements, with slightly low levels of serum copper and ceruloplasmin, and markedly low excretion of urinary copper. We propose that the unique combination of dementia, dysarthria, gait disturbances, involuntary movements and abnormalities of copper metabolism does not fit any known nosological entity and constitutes a "new" syndrome different from Wilson's and Menkes' diseases.

Rimmed vacuolar distal myopathy: a clinical, electrophysiological, histopathological and computed tomographic study of seven cases

The following report describes the clinical, laboratory, electrophysiological, histopathological and computed tomographic studies of seven cases of distal myopathy with rimmed vacuoles in the muscle fibers. Each displayed several characteristic features. First, the onset was in early adulthood. Second, there was a unique distribution of muscle involvement: tibialis anterior and extensor digitorum and hallucis muscles were initially and most severely affected. The hamstrings and adductors of the thigh were also markedly involved. The gluteus medius and minimus muscles and the neck flexors were mildly affected in the relatively early stages. In contrast, the gastrocnemius, soleus, quadriceps femoris, and gluteus maximus muscles were well preserved until an advanced stage. Third, serum creatine kinase activity was normal or only mildly elevated; fourth, EMG were mainly myopathic, with certain neuropathic features; and fifth, histopathologically rimmed vacuoles in muscle fibers were found associated with certain "neuropathic" features, such as angular fibers, clustering of atrophic fibers, pyknotic nuclear clumps, and fiber-type predominance. The characteristic distribution of skeletal muscle involvement was particularly noticeable, together with certain "neuropathic" features of the EMG and muscle biopsy in rimmed vacuolar distal myopathy.

Rimmed vacuolar distal myopathy. An ultrastructural study

An ultrastructural study of biopsied muscles was performed in seven patients with rimmed vacuolar distal myopathy, which was characterized by prominent rimmed vacuoles in the muscle fibers. The earliest changes noted were focal proliferation of the Golgi's apparatus and mitochondrial degeneration with myofibrillar loss. A proliferation of the T-system appeared later. Secondary lysosomes (autophagosomes) could be noted much later and gradually increased in number. Autophagosomes tended to coalesce and became larger autophagic vacuoles, which were surrounded in part by relatively preserved myofibrils and partly by a single membrane. Gently curved laminated structures (tubulomembranous structures) were seen in the degenerating muscle fibers and also in relatively intact fibers, satellite cells, and interstitial cells in all cases. They were closely associated with lipofuscin-like material. These findings suggest that an abnormality of the lysosomal system might be essential in the pathogenesis of rimmed vacuolar distal myopathy.

"Ragged-red" fibres in myotonic dystrophy

Twenty-five muscle biopsies (18 from the left biceps and 7 from the left quadriceps) of 25 patients suffering from myotonic dystrophy (MyD) were studied, 13 of which showed "ragged-red" fibres (RRFs); all the RRFs, which were type I fibres, were found in biceps muscles, while none of the quadriceps muscles showed RRFs. The incidence of RRFs varied from 0.5% to 20.0% (average 4.2%). On electron microscopy, RRFs contained enlarged mitochondria, usually in subsarcolemmal clusters, including dense granular matrix materials, concentrically whired membranous cristae, and paracrystalline inclusions, consistent with those of previously reported cases of mitochondrial myopathy, suggesting that RRFs observed in biopsies from patients with MyD are due to abnormal mitochondria. The biopsy findings indicative of MyD including pyknotic nuclear clumps, moth-eaten fibres, ring fibres, type I fibre atrophy, and type I fibre predominance, were much more common findings in biceps muscles than quadriceps muscles, and in biopsies with RRFs than those without RRFs. From our observations, it is possible that RRFs in biopsied muscles from patients with MyD are not incidental observations but are intimately associated with the pathogenesis of this disorder, and that RRFs may be a special form of pathological reaction in which accumulation of abnormal mitochondria occurs.

Studies on neurotransmitter markers and neuronal cell density in the cerebellar system in olivopontocerebellar atrophy and cortical cerebellar atrophy

Glutamate, aspartate and gamma-aminobutyrate (GABA) concentrations and choline acetyltransferase (ChAT) activity were measured in postmortem cerebellar cortical areas and brainstem nuclei of 10 normal controls, 5 patients of olivopontocerebellar atrophy (OPCA) with multiple system atrophy (MSA) and 2 patients of cortical cerebellar atrophy (CCA). In addition, the neuronal cell density in the cerebellar cortex and the brainstem nuclei was determined, and the correlation between neurotransmitter markers and the neuronal cell densities were investigated. Glutamate and aspartate concentrations in the cerebellar cortical tissues were markedly varied from case to case of MSA (OPCA) and CCA patients. However, glutamate concentration in the anterior vermis showed a positive correlation coefficient with the density of granule cells (r = 0.554, 0.05 less than P less than 0.10) and, those in the posterior vermis and in the cerebellar hemisphere were positively correlated with cells in the inferior olive (r = 0.707 and 0.607, P less than 0.05, respectively). Aspartate concentration in the anterior vermis also has a positive correlation coefficient (r = 0.571, 0.05 less than P less than 0.10) with the density of cells in the inferior olive. GABA concentrations in the dentate nucleus were decreased in all cases of MSA (OPCA) and CCA, and were positively correlated with the degree of loss of Purkinje cells (r = 0.765, P less than 0.01). ChAT activities were decreased in certain cases of MSA (OPCA), but conversely, increased in CCA patients. ChAT activity in the posterior vermis has a positive correlation coefficient (r = 0.613, 0.05 less than P0.10) with the cell density in the pontine nucleus. A possibility of a compensatory increase of ChAT activity in CCA patients was discussed.