Neuropathic pain correlates with myelinated fibre loss and cytokine profile in POEMS syndrome.

OBJECTIVE: To reveal characteristic clinicopathological correlates of polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes (POEMS) syndrome. METHODS: The clinical features of 22 patients with POEMS syndrome were investigated and correlated with the histopathological features of sural nerves and serum cytokine profiles. RESULTS: More than half of the patients complained of pain in the lower extremities, which is closely related to hyperalgesia. Assessment of the total nerve fibre population using complete transverse sural nerve cross-sections, excluding the marked enlargement of endoneurial areas due to intrafascicular oedema, showed that myelinated fibres, especially small myelinated fibres, were reduced, whereas unmyelinated fibres were preserved. Uncompacted myelin lamellae and segmental demyelination were seen more frequently in the small, rather than the large, myelinated fibres. The presence of hyperalgesia was electrophysiologically associated with a reduction of sensory nerve action potentials in the sural nerve (p<0.05) and histopathologically associated with myelinated fibre loss (p<0.01). Serum levels of proinflammatory cytokines (interleukin-1beta, interleukin-6 and tumour necrosis factor-alpha), but not their soluble receptors, were significantly elevated in patients with hyperalgesia (p<0.05-0.01). CONCLUSIONS: Hyperalgesia seen in patients with POEMS syndrome is closely related with a reduction in the myelinated, but not unmyelinated, fibre population. Elevation of proinflammatory cytokines is also correlated with hyperalgesia. The painful symptoms in POEMS syndrome may be generated by well-preserved unmyelinated C-fibres due to the lack of inhibitory myelinated A-fibres, along with cytokine sensitisation.

Pathogenesis and molecular targeted therapy of spinal and bulbar muscular atrophy.

Spinal and bulbar muscular atrophy (SBMA) or Kennedy's disease is a motor neurone disease characterized by muscle atrophy, weakness, contraction fasciculations and bulbar involvement. SBMA mainly affects males, while females are usually asymptomatic. SBMA is caused by expansion of a polyglutamine (polyQ)-encoding CAG trinucleotide repeat in the androgen receptor (AR) gene. AR belongs to the heat shock protein 90 (Hsp90) client protein family. The histopathologic hallmarks of SBMA are diffuse nuclear accumulation and nuclear inclusions of the mutant AR with expanded polyQ in residual motor neurones in the brainstem and spinal cord as well as in some other visceral organs. There is increasing evidence that the ligand of AR and molecular chaperones play a crucial role in the pathogenesis of SBMA. The success of androgen deprivation therapy in SBMA mouse models has been translated into clinical trials. In addition, elucidation of its pathophysiology using animal models has led to the development of disease-modifying drugs, that is, Hsp90 inhibitor and Hsp inducer, which inhibit the pathogenic process of neuronal degeneration. SBMA is a slowly progressive disease by nature. The degree of nuclear accumulation of mutant AR in scrotal skin epithelial cells was correlated with that in spinal motor neurones in autopsy specimens; therefore, the results of scrotal skin biopsy may be used to assess the efficacy of therapeutic trials. Clinical and pathological parameters that reflect the pathogenic process of SBMA should be extensively investigated.

ABO-incompatible auxiliary partial orthotopic liver transplant for late-onset familial amyloid polyneuropathy.

A 60-year-old Japanese man with late-onset familial amyloid polyneuropathy type I (FAP transthyretin Met30) showed clinical improvement following auxiliary partial orthotopic liver transplantation (APOLT) from an ABO-incompatible living related donor. Preoperatively, plasmapheresis and immunosuppressant drugs were used to reduce serum antibodies against the donor's ABO type. APOLT was chosen so the residual liver could sustain the patient in the event of hyperacute rejection. OLT is applicable to late-onset FAP transthyretin Met30, and APOLT can be considered in ABO-incompatible cases.

Cardiac (123)I-meta-iodobenzylguanidine (MIBG) uptake in dementia with Lewy bodies: comparison with Alzheimer's disease.

Cardiac (123)I-meta-iodobenzylguanidine (MIBG) uptake was measured in 11 patients with dementia with Lewy bodies (DLB), 10 patients with Alzheimer's disease (AD), and 10 age matched control subjects. The severity of cognitive impairment and duration of symptoms in patients with DLB matched that in the patients with AD. The heart/mediastinum (H/M) ratio of MIBG uptake in the patients with AD was indistinguishable from that in the control subjects. However, the H/M ratio in all patients with DLB was significantly lower than that in the patients with AD and control subjects (p<0.001). These findings indicate that local myocardial sympathetic nerves are affected in DLB and that cardiac (123)I-MIBG scintigraphy may provide a means of differentiating DLB from AD.

Transgenic mice with an expanded CAG repeat controlled by the human AR promoter show polyglutamine nuclear inclusions and neuronal dysfunction without neuronal cell death.

We generated transgenic mice that expressed a highly expanded 239 polyglutamine (polyQ) repeat under the control of the human androgen receptor promoter. These transgenic mice developed progressive neurological phenotypes of muscular weakness and ataxia, small body size and short life-span. PolyQ nuclear inclusions (NIs) were remarkable and widespread but found in selective regions of the central nervous system (CNS) such as the spinal cord, cerebrum and cerebellum as well as in selective peripheral visceral organs. This distribution pattern resembled that of spinal and bulbar muscular atrophy somewhat, but was more widespread. In neuronal tissues, NIs were present in astrocytes as well as neurons. Cytoplasmic and axonal inclusions were not observed. In the CNS regions with abundant NIs, neuronal populations were well-preserved, and neither neuronal cell death, reactive astrogliosis nor microglial invasions were detected. These findings suggest that polyQ alone can induce the neuronal dysfunction that precedes gross neuronal degeneration and provides a clue for investigating molecular mechanisms that underly the pathway to neuronal dysfunction from polyQ expansion.

A rescue factor abolishing neuronal cell death by a wide spectrum of familial Alzheimer's disease genes and Abeta.

Through functional expression screening, we identified a gene, designated Humanin (HN) cDNA, which encodes a short polypeptide and abolishes death of neuronal cells caused by multiple different types of familial Alzheimer's disease genes and by Abeta amyloid, without effect on death by Q79 or superoxide dismutase-1 mutants. Transfected HN cDNA was transcribed to the corresponding polypeptide and then was secreted into the cultured medium. The rescue action clearly depended on the primary structure of HN. This polypeptide would serve as a molecular clue for the development of new therapeutics for Alzheimer's disease targeting neuroprotection.

A novel centrosomal ring-finger protein, dorfin, mediates ubiquitin ligase activity.

We cloned a novel gene, Dorfin (double ring-finger protein), from human spinal cord. The Dorfin mRNA transcript was 4.4 kb and expressed ubiquitously in many organs as well as in the central nervous system, including the spinal cord. Dorfin encoded 838 amino acid protein Dorfin, which contains two RING-finger motifs and an IBR (in between RING-fingers) motif at its N-terminus. Dorfin is a short-lived protein. Treatment with MG132, a potent proteasome inhibitor, resulted in the accumulation of ubiquitinated Dorfin and Dorfin-associated cellular proteins in cultured cells. Dorfin bound specifically with human ubiquitin-conjugating enzymes UbcH7 and UbcH8 through the RING-finger/IBR domain. Partial deletion of the RING-finger/IBR domain eliminated these interaction and ubiquitination activities. These results strongly suggest that Dorfin is a new member of RING-finger type ubiquitin ligase. Dorfin is localized in the centrosome and probably functions in the microtubule organizing centers.

Gene expression profile in Alzheimer's brain screened by molecular indexing.

Gene expression in the Alzheimer brain and normal brain was compared by molecular indexing, an advanced version of differential display. Using this technique, each gene was represented by a 3'-end cDNA fragment generated by class IIS restriction enzymes. The fragments were divided into 384 groups, and each group was separated by denaturing polyacrylamide gel electrophoresis. Comparison of gel patterns revealed 70 genes exhibiting marked differences in gene expression between AD and normal brain. A similarity search revealed 22 genes already reported, including those considered to be related to the pathogenesis such as G protein, G protein-related, and mitochondrial components. Detailed analysis of one from those only matched to EST sequences revealed a novel protein with leucine-zipper and SH3-binding motifs. Its expression was suppressed in a subpopulation of cortical pyramidal neurons in the AD brain, suggesting a possible relation to the pathogenesis. Thus, genome-scale analysis of gene expression of neurodegeneration is a potentially powerful approach to listing genes related to the pathogenesis.

Two novel genes, human neugrin and mouse m-neugrin, are upregulated with neuronal differentiation in neuroblastoma cells.

We herein report two new genes, human neugrin and mouse homologue m-neugrin, found by screening the cDNA library for the human spinal cord. The neugrin mRNA encodes 219 amino acids and its deduced amino acid sequence contains an NLS-like domain. No previously known motif is found in it. m-neugrin mRNA encodes 233 amino acids. Neugrin and m-Neugrin are 70% homologous in amino acid sequence. Northern analysis revealed that neugrin was strongly expressed in the heart, brain, and skeletal muscle, and m-neugrin in the liver, kidney, and brain. A transfection study indicated that these proteins are localized in the nucleus. Although the expression of neugrin was found to be ubiquitous in the nervous system, in situ hybridization showed that both neugrin and m-neugrin were expressed mainly in the neurons rather than the glial cells. Their expression was highly upregulated with the neurite outgrowth associated with neuronal differentiation in neuroblastoma cell lines. These results indicate that neugrin and m-neugrin are mainly expressed in neurons in the nervous system, and play an important role in the process of neuronal differentiation.

The role of lymphotoxin in pathogenesis of polymyositis.

Polymyositis (PM) is a cell-mediated autoimmune disease. Perforin (PF), Fas ligand (FasL) and TNF-alpha are considered to be important factors in cytotoxic T lymphocyte-mediated cell injury, and several studies have established a role of lymphotoxin (LT) in T helper type 1 (Th1)-induced cell-mediated autoimmune diseases. In the present study, to determine how LT, PF and FasL are involved in the pathogenesis of PM, we used immunohistochemical staining (IHC), reverse transcription polymerase chain reaction (RT-PCR), and in situ hybridization (ISH) on muscle specimens from patients with PM, amyotrophic lateral sclerosis (ALS), myotonic dystrophy (MyD) and controls (NC). There were many mononuclear cells (MNCs) immunoreactive for LT and some for PF and FasL within the fasciculus in PM muscles. On the other hand, only few or no LT-, PF- and FasL-positive cells were detected in MyD, ALS and NC muscles. The results of mRNA expression of these three molecules with RT-PCR were consistent with those using IHC methods. The number of MNCs positive for LT with ISH was far higher in PM compared to MyD, ALS and NC (P < 0.05 or 0.01). The MNCs located in the connective tissue or in the vicinity of necrotizing or non-necrotizing muscles were mainly LT mRNA and CD4 positive, while MNCs invading the non-necrotic fibers were mainly LT mRNA and CD8 positive. Our results indicated that the expression of LT was up-regulated in PM, and LT plays an important role in muscle injury and orchestrating the inflammatory reaction in PM.

Detection of triplet repeat expansion in the human genome by use of hybridization signal intensity.

Triplet repeat disease is a group of hereditary neurodegenerative disorders caused by expansion of trinucleotide repeats such as CAG/CTG, CGG/CCG, and GAA/TTC. Direct detection of the expansion in the patient's genome shortcuts the tedious process needed for identification of disease genes by conventional approaches. Here we describe a method to detect triplet repeat expansion from the hybridization signal intensity. Using a digoxigenin-labeled (CTG)9 probe, the hybridization intensity and number of repeats showed a good linear correlation. The technique detected expansion in genomic DNA in all cases with moderate or large expansion. Even in the case of a small expansion, this method could detect the mutant fragment. The technique has advantages over related techniques because it is more sensitive and can be applied to cases where a small repeat expansion is involved.

Temporal expression of mRNAs for neuropoietic cytokines, interleukin-11 (IL-11), oncostatin M (OSM), cardiotrophin-1 (CT-1) and their receptors (IL-11Ralpha and OSMRbeta) in peripheral nerve injury.

The mRNA expression pattern of the neuropoietic cytokines, interleukin-11 (IL-11), oncostatin M (OSM) and cardiotrophin-1 (CT-1), and their receptor components (IL-11Ralpha and OSMRbeta) was examined in peripheral nerves on two different types of injury, crush and transection. The IL-11 mRNA increased after nerve damage and immediately returned to control levels. The OSM mRNA expression increased rapidly after nerve injury and relatively high expressions were maintained for at least 14 days. The CT-1 mRNA was not expressed in any time before and after the injury. Interestingly, IL-11Ralpha was expressed in the intact nerve and decreased after injury. The expression of OSMRbeta increased slightly after the injury. Moreover, temporal mRNA expression pattern of these neuropoietic cytokines and receptors was similar between the crushed and transected models. Each neuropoietic cytokine of IL-11, OSM and CT-1 has its own specific temporal mRNA expression pattern, which is also different from those of ciliary neuro-trophic factor (CNTF), leukemia inhibitory factor (LIF) and interleukin-6 (IL-6). These results suggest that all neuropoietic cytokines have distinctive functions in nerve degeneration and repair process in response to peripheral nerve injury.

Reduced expression of DMAHP/SIX5 gene in myotonic dystrophy muscle.

In myotonic dystrophy (DM), the expansion of CTG triplet repeats in the 3'-untranslated region of DM-protein kinase (DMPK) is a causal gene mutation. However, the pathogenic molecular mechanism of CTG repeat expansion for DM phenotypic expression is unclear. To investigate this issue, we examined the influence of CTG repeat expansion on the expression levels of DMPK gene and 3'-flanking DM locus-associated homeodomain protein (DMAHP)/SIX5 gene in the muscles of DM patients. We isolated RNA from muscle tissues of six DM patients and six controls, and performed a competitive reverse transcriptional polymerase chain reaction (RT-PCR) assay. The total mRNA level of DMAHP/SIX5 was significantly lower in DM than in controls, but the DMPK mRNA level was unchanged. Our results suggest that CTG repeat expansion influences the expression of genes other than DMPK to cause the DM phenotype.

Mutations in the peripheral myelin protein zero and connexin32 genes detected by non-isotopic RNase cleavage assay and their phenotypes in Japanese patients with Charcot-Marie-Tooth disease.

Mutations of myelin protein zero (MPZ) and connexin32 (Cx32) genes were examined in 70 unrelated Japanese patients with Charcot-Marie-Tooth disease (CMT) without PMP22 gene duplication. A new method, which could detect base pair mismatches with Rnase cleavage on agarose gel electrophoresis, identified 5 and 4 mutations of the MPZ and Cx32 genes, respectively, including one novel mutation (Ser128Ter) of Cx32. This non-isotopic RNase cleavage assay (NIRCA) employed in the present study is very suitable for exploring mutations of MPZ and Cx32 genes in a large number of CMT patients, as the phenotype of patients with CMT is greatly divergent from demyelinating to axonal pathology.

Sisters homozygous for the spinocerebellar ataxia type 6 (SCA6)/CACNA1A gene associated with different clinical phenotypes.

Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disease caused by a CAG repeat expansion in the CACNA1A gene. The neurodegeneration that occurs in CAG repeat diseases is considered to share a common mechanism that may result in the gain of a toxic function related to the expanded polyglutamine tracts. However, the phenotypic expression in homozygotes for CAG repeat diseases has been controversial, and is not clearly related to a gain of functional mechanism. We identified a Japanese family with two sisters who were homozygous for the SCA6 with identical CAG repeat expansion (25/25). They showed an earlier age of onset (27 years in both) than their father (44 years), a heterozygote with an expanded allele showing the same CAG repeat length as the homozygotes (25/14). Interestingly, the two sisters showed differences in disease progression and severity, although the age of onset and CAG repeat length were identical. These findings strongly suggest that the gene dosage influences the age of onset, but other unknown factors are also important in the phenotypic expression of homozygous SCA6.

[CNS cryptococcosis with idiopathic CD4+ T lymphocytopenia].

A 33-year-old Japanese man, with a history of recurrent skin cryptococcosis, was admitted complaining of fever and severe headache for 3 weeks. He had no known risk factors for human immunodeficiency virus (HIV) infection. Cerebrospinal fluid examination revealed an elevated opening pressure of 32 cm H2O, cell counts of 884/mm3, a total protein value of 184 mg/dl, a glucose level of 16 mg/dl, and demonstrated a positive India ink stain for fungus. Cultures grew Cryptococcus neoformans. Hematological studies showed a persistently low CD4+ cell count (30/mm3) and a low CD4/CD8 ratio of 0.1. He has been repeatedly seronegative (ELISA and Western blot) for HIV-1 and HIV-2. He responded to fluconazole, and was given itraconazole as secondary prophylaxis because of persistent low CD4 counts. To our knowledge this is the first patient with idiopathic CD4+ T lymphocytopenia associated with CNS cryptococcosis in Japan. CD4 counts should be part of the initial work up for patients with CNS cryptococcosis.

Tumor necrosis factor-alpha expression in muscles of polymyositis and dermatomyositis.

We evaluated the expression of tumor necrosis factor-alpha (TNF-alpha) mRNA in muscle biopsy specimens from patients with polymyositis (PM) and dermatomyositis (DM) to clarify its role in the pathogenesis of PM and DM. We performed non-radioactive in situ hybridization studies for TNF-alpha combined with immunohistochemistry for cell type-specific markers on muscles from ten PM and five DM patients. TNF-alpha-positive infiltrating cells present in the endomysium and perimysium were found in all PM and DM muscles. The frequency of TNF-alpha-positive cells against total infiltrating cells was similar among PM and DM (27.1 +/- 7.4% in PM and 28.5 +/- 13.6% in DM). However, TNF-alpha/CD8-positive lymphocytes and TNF-alpha-positive macrophages invading the non-necrotic muscle fiber were observed only in PM but not in DM. TNF-alpha was more highly expressed in PM and DM than was previously thought, and it was suggested that TNF-alpha plays a role in muscle fiber degeneration in PM.

An autopsy case with clinically and molecular genetically diagnosed Huntington's disease with only minimal non-specific neuropathological findings.

An autopsy case with clinically and molecular genetically diagnosed Huntington's disease (HD) accompanied with minimal non-specific neuropathological features was reported. When the patient was 45 years old, he had faulty memory, mood swing, personality change and agitation. Neurological and psychiatric examinations revealed choreoathetoid movements in limbs and trunk, generalized hyperreflexia and mental deterioration. However, cerebellar ataxia and muscle rigidity were not disclosed. Neuroimaging study did not show a definite atrophy of heads of caudate nuclei. Neuroacanthocytosis and Wilson's disease were ruled out by the peripheral blood examination and serum Cu and ceruloplasmin examination. At the age of 55 he died of pneumonia. Post-mortem examination revealed minimal non-specific neuropathological features for HD (Vonsattel's grade 0), that is, no visible fibrillary gliosis in the striatum, and few neuronal loss and only proliferation of astrocytes (astrocytosis) in the striatum. Molecular-genetic study the patient's brain tissues and his youngest son's blood was performed. These studies revealed 40 CAG repeats in the patient, 56 CAG repeats in his youngest son. These results suggest they may be HD. Vonsattel et al. [ 1998] insist that grade 0 comprises 1% of all HD brains, and grade 1 comprises 4% of all HD brains. But we could not find any reports in which the clinical and neuropathological features were described in detail on the cases with clinically and molecular genetically diagnosed HD without specific pathological findings. Therefore, we present in detail the clinical and neuropathological features of such case.

Chaperones Hsp70 and Hsp40 suppress aggregate formation and apoptosis in cultured neuronal cells expressing truncated androgen receptor protein with expanded polyglutamine tract.

Spinal and bulbar muscular atrophy (SBMA) is one of a group of human inherited neurodegenerative diseases caused by polyglutamine expansion. We have previously demonstrated that the SBMA gene product, the androgen receptor protein, is toxic and aggregates when truncated. Heat shock proteins function as molecular chaperones, which recognize and renaturate misfolded protein (aggregate). We thus assessed the effect of a variety of chaperones in a cultured neuronal cell model of SBMA. Overexpression of chaperones reduces aggregate formation and suppresses apoptosis in a cultured neuronal cell model of SBMA to differing degrees depending on the chaperones and their combinations. Combination of Hsp70 and Hsp40 was the most effective among the chaperones in reducing aggregate formation and providing cellular protection, reflecting that Hsp70 and Hsp40 act together in chaperoning mutant and disabled proteins. Although Hdj2/Hsdj chaperone has been previously reported to suppress expanded polyglutamine tract-formed aggregate, Hsdj/Hdj2 showed little effect in our system. These findings indicate that chaperones may be one of the key factors in the developing of CAG repeat disease and suggested that increasing expression level or enhancing the function of chaperones will provide an avenue for the treatment of CAG repeat disease.