Physical interactions among flavonoid enzymes in snapdragon and torenia reveal the diversity in the flavonoid metabolon organization of different plant species

Flavonoid metabolons (weakly-bound multi-enzyme complexes of flavonoid enzymes) are believed to occur in diverse plant species. However, how flavonoid enzymes are organized to form a metabolon is unknown for most plant species. We analyzed the physical interaction partnerships of the flavonoid enzymes from two lamiales plants (snapdragon and torenia) that produce flavones and anthocyanins. In snapdragon, protein-protein interaction assays using yeast and plant systems revealed the following binary interactions: flavone synthase II (FNSII)/chalcone synthase (CHS); FNSII/chalcone isomerase (CHI); FNSII/dihydroflavonol 4-reductase (DFR); CHS/CHI; CHI/DFR; and flavonoid 3'-hydroxylase/CHI. These results along with the subcellular localizations and membrane associations of snapdragon flavonoid enzymes suggested that FNSII serves as a component of the flavonoid metabolon tethered to the endoplasmic reticulum (ER). The observed interaction partnerships and temporal gene expression patterns of flavonoid enzymes in red snapdragon petal cells suggested the flower stage-dependent formation of the flavonoid metabolon, which accounted for the sequential flavone and anthocyanin accumulation patterns therein. We also identified interactions between FNSII and other flavonoid enzymes in torenia, in which the co-suppression of FNSII expression was previously reported to diminish petal anthocyanin contents. The observed physical interactions among flavonoid enzymes of these plant species provided further evidence supporting the long-suspected organization of flavonoid metabolons as enzyme complexes tethered to the ER via cytochrome P450, and illustrated how flavonoid metabolons mediate flower coloration. Moreover, the observed interaction partnerships were distinct from those previously identified in other plant species (Arabidopsis thaliana and soybean), suggesting that the organization of flavonoid metabolons may differ among plant species.

Rapid nongenomic modulation by neurosteroids of dendritic spines in the hippocampus: Androgen, oestrogen and corticosteroid

Memories are stored in synapses that consist of axon terminals and dendritic spines. Dendritic spines are postsynaptic structures of synapses and are essential for synaptic plasticity and cognition. Therefore, extensive investigations concerning the functions and structures of spines have been performed. Sex steroids and stress steroids have been shown to modulate hippocampal synapses. Although the rapid modulatory action of sex steroids on synapses has been studied in hippocampal neurones over several decades, the essential molecular mechanisms have not been fully understood. Here, a description of kinase-dependent signalling mechanisms is provided that can explain the rapid nongenomic modulation of dendritic spinogenesis in rat and mouse hippocampal slices by the application of sex steroids, including dihydrotestosterone, testosterone, oestradiol and progesterone. We also indicate the role of synaptic (classic) sex steroid receptors that trigger these rapid synaptic modulations. Moreover, we describe rapid nongenomic spine modulation by applying corticosterone, which is an acute stress model of the hippocampus. The explanations for the results obtained are mainly based on the optical imaging of dendritic spines. Comparisons are also performed with results obtained from other types of imaging, including electron microscopic imaging. Relationships between spine modulation and modulation of cognition are discussed. We recognise that most of rapid effects of exogenously applied oestrogen and androgen were observed in steroid-depleted conditions, including acute slices of the hippocampus, castrated male animals and ovariectomised female animals. Therefore, the previously observed effects can be considered as a type of recovery event, which may be essentially similar to hormone replacement therapy under hormone-decreased conditions. On the other hand, in gonadally intact young animals with high levels of endogenous sex hormones, further supplementation of sex hormones might not be effective, whereas the infusion of blockers for steroid receptors or kinases may be effective, with respect to suppressing sex hormone functions, thus providing useful information regarding molecular mechanisms.

Disease-modifying agents in the Sonya Slifka Longitudinal Multiple Sclerosis Study

Background

Although experts recommend that people with multiple sclerosis (MS) should begin treatment with disease-modifying agents (DMAs) as soon as possible after diagnosis and continue indefinitely, many do not use these agents or discontinue them prematurely. Since DMAs reduce relapse rates and slow disease progression, and since even benign relapses and course can lead to axonal damage and permanent neurologic impairment, it is important that all appropriate candidates have access to treatment. We used a population-based sample of people with MS to determine rates, predictors, and reasons for use, non-use, and discontinuation of DMAs.

Methods

We collected data from 2156 people with MS on their use of and experience with DMAs. We used chi-squared tests to compare current, past, and never users of any DMA and ever users of individual DMAs, and logistic regression to identify predictors of use.

Results

One-half of the participants were using a DMA at the time of the interview; 12.2% had used previously, but stopped. Reasons for never using and reasons for stopping were at odds with expert recommendations. Characterization of users, and of their experiences by type of DMA, was consistent with current knowledge of these agents. Seeing a neurologist for usual MS care was an important factor in starting and persisting with DMA therapy.

Conclusions

Dissemination of expert opinion about, and management strategies for, use of DMAs to non-neurologic professionals and patients and their families might help more people who are appropriate candidates for DMA therapy to start and continue treatment.

Palladium-catalysed cascade ring expansion reaction of cyclobutanols that have a propargylic moiety with nucleophiles

Cascade ring rearrangement of four-membered ring systems containing various propargylic components by a palladium catalyst is described. The reactions of cyclobutanols that have a propargylic carbonate moiety with phenols as nucleophiles produce phenoxy-induced cyclopentanones in high yields. The reactions proceed in a regio- and diastereoselective manner to afford the substituted cyclopentanones with high selectivities. Imides also act as nucleophiles to produce the imidyl-induced products. Propargylic bromide successfully reacts with sodium alkoxides to produce the corresponding products in good yields.

Progressive supranuclear palsy presenting with primary progressive aphasia--clinicopathological report of an autopsy case

We report a Japanese autopsy case of progressive supranuclear palsy (PSP). The male patient was 74 years old at the time of death. At age 64, he developed non-fluent aphasia that progressed slowly over 8 years, eventually associated with behavioral abnormality, postural instability, and dysphagia at 2 years prior to his death. Magnetic resonance imaging of the brain at age 73 demonstrated marked atrophy of the frontal lobes, particularly on the left side. Neuropathological examination revealed the typical pathology of PSP: loss of neurons, gliosis, occurrence of neurofibrillary tangles, oligodendroglial coiled bodies, and tuft-shaped astrocytes in the frontal cortex, associated with argyrophilic threads in the underlying white matter, in the basal ganglia, including the thalamus, globus pallidus, and subthalamic nucleus, and in the brainstem nuclei, including the substantia nigra, pontine nucleus, and inferior olivary nucleus. No astrocytic plaques or ballooned neurons were observed. Protein analysis revealed accumulation of hyperphosphorylated tau of 68 and 64 kDa consisting of the four repeat tau isoforms. We conclude that the present case represented PSP with an 8-year history of primary progressive aphasia (PPA). Although focal cortical symptoms in PSP are rare or absent, we should keep in mind the possibility of atypical PSP in which cortical pathology is predominant, particularly in the frontal lobe, and could result in PPA.

[A 64-year-old man with parkinsonism as an initial symptom followed by dementia associated with marked abnormal behaviours]

We report a 64-year-old man with parkinsonism as an initial symptom, which was followed by dementia and abnormal behaviours. He was well until 1985, when he was 49 years old, when he noted rest tremor in his right hand. Soon tremor appeared in his left hand as well. He was seen in our clinic and levodopa was prescribed. He was doing well with this medication, however, in 1993, he started to suffer from on-off phenomenon. He also noted visual hallucination. In 1994, he stole a watermelon and ate it in the shop. He repeated such abnormal behaviours. In 1995, he was admitted to the neurology service of Hatsuishi Hospital. On admission, he was alert and oriented. He did not seem to be demented; however, he admitted stealing and hypersexual behaviours. No aphasia, apraxia, or agnosia was noted. In the cranial nerves, downward gaze was markedly restricted. He showed masked and seborrhoic face, and small voice. No motor palsy was noted, but he walked in small steps with freezing and start hesitation. Marked neck and axial rigidity was noted. Tremor was absent except for in the tongue. No cerebellar ataxia was noted. Deep tendon reflexes were diminished. Plantar response was extensor bilaterally. Forced grasp was noted also bilaterally. He was treated with levodopa and pergolide, but he continued to show on-off phenomenon. His balance problem and akinesia became progressively worse; still he showed hypersexual behaviour problems. He also showed progressive decline in cognitive functions. In 1997, he started to show dysphagia. He developed aspiration pneumonia in July of 1998. In 1999, he developed emotional incontinence and became unable to walk. He also developed repeated aspiration pneumonia. He died on March 1, 2000. He was discussed in a neurological CPC and the chief discussant arrived at a conclusion that the patient had corticobasal degeneration. Other diagnoses entertained included dementia with Lewy bodies, diffuse Lewy body disease, and frontotemporal dementia. Majority of the participants thought that diffuse Lewy body disease was most likely. Post-mortem examination revealed marked nigral neuronal loss, gliosis and Lewy bodies in the remaining neurons. Abundant Lewy bodies of cortical type were seen wide spread in the cortical areas, but particularly many in the amygdaloid nucleus. Lewy bodies were also seen in the subcortical structures such as the dorsal motor nucleus, oculomotor nucleus, Meynert nucleus, putamen, and thalamus. What was interesting was marked neuronal loss of the pontine nuclei, demyelination of the pontocerebellar fiber, and moderate neuronal loss of the cerebellar Purkinje neurons, a reminiscent of pontocerebellar atrophy. However, the inferior olivary nucleus was intact.

[An 84-year-old woman with progressive mental deterioration and abnormal behavior]

We report an 84-year-old woman with progressive mental deterioration. She was well until January 1994, when she was 80 years of the age. At that time she developed a delusional ideation, in that she stated that she would be killed by her fellow members of the society for elderly, in which she was belonging. At times, she closed the shutter of her house saying that a stranger was wandering outside of her house. In 1995, she could not identify the face of her son's wife. When she went out for shopping, she lost her way to the home. She prowled about in and out of her home. In 1996, she had to be admitted to a nursing home, where quarrelled with other patients and behaved violently. She was admitted to the neurology service of Hatsuishi Hospital on November 20th, 1997. Family history revealed that her mother was said to be demented. On admission, she was alert and behaved in a good manner. She was disoriented to the time and unable to do serial 7. Her memory was very poor. She did not show aphasia or apraxia. Cranial nerves appeared to be intact. She showed no weakness or muscle atrophy. Gait was normal for her age. Plastic rigidity was noted in four limbs more on the right side. No ataxia was noted. Deep tendon reflexes were exaggerated, however, no Babinski sign was noted. Sensory examination was intact. Her hospital course was characterized by the development of progressive gait disturbance, violent behaviour, and prowling around. On November 30th, 1998, she fell down and suffered from a fracture in the neck of her femur. Although replacement of the femur head was performed, she became unable to walk after this episode. Her mental functions deteriorated further. She developed pneumonia and expired on February 2, 1999. She was discussed in a neurological CPC and the chief discussant arrived at a conclusion that the patient probably had diffuse Lewy body disease, because of the combination of dementia and parkinsonism. Other possibilities discussed in the CPC included Pick's disease, frontotemporal dementia and parkinsonism, and Alzheimer's disease. Post-mortem examination revealed moderate atrophy in the frontal and temporal cortices. Microscopic examination showed atrophy and gliosis in the hippocampus. Many diffuse plaque and neuritic plaques were seen in the frontal cortex by methenamine silver staining. Neurofibrillary tangles were also found. The Meynert nucleus was preserved. The putamen and the substantia nigra were also intact. Pathologic diagnosis was consistent with Alzheimer's disease.

Abeta42-positive non-pyramidal neurons around amyloid plaques in Alzheimer's disease

Immunohistochemistry with end-specific antibodies against C-termini of Abeta40 and Abeta42 in Alzheimer's disease showed that Abeta42 immunoreactivity was localised intracellularly in subpopulations of neurons of patients with Alzheimer's disease.

Clinical, neuropathological, and molecular study in two families with spinocerebellar ataxia type 6 (SCA6)

To clarify the clinical, neuropathological, and molecular characteristics of spinocerebellar ataxia type 6 (SCA6), two unrelated Japanese families with SCA6 were studied. A clinical feature of the two families was late onset "pure" cerebellar ataxia. Pathologically, three SCA6 brains consistently showed Purkinje cell dominant cortical cerebellar degeneration. Morphometric analysis showed that loss of the cerebellar granule cells and inferior olivary neurons were very mild compared with the severity of Purkinje cell loss. There was no obvious ubiquitin immunoreactive nuclear inclusions. All affected patients had identical expanded alleles, and the expansion was also homogeneously distributed throughout the brain without mosaicism. The present study showed that SCA6 is characterised by Purkinje cell dominant cortical cerebellar degeneration, highly stable transmission of the CAG repeat expansion, and lack of ubiquitin immunoreactive nuclear inclusions.

Abundant expression and cytoplasmic aggregations of [alpha]1A voltage-dependent calcium channel protein associated with neurodegeneration in spinocerebellar ataxia type 6

Spinocerebellar ataxia type 6 (SCA6) is one of the eight neurodegenerative diseases caused by a tri-nucleotide (CAG) repeat expansion coding polyglutamine (CAG repeat/polyglutamine diseases) and is characterized by late onset autosomal dominant cerebellar ataxia and predominant loss of cerebellar Purkinje cells. Although the causative, small and stable CAG repeat expansion for this disease has been identified in the [alpha]1A voltage-dependent calcium channel gene (CACNA1A), the mechanism which leads to predominant Purkinje cell degeneration is totally unknown. In this study, we show that the calcium channel mRNA/protein containing the CAG repeat/polyglutamine tract is most intensely expressed in Purkinje cells of human brains. In SCA6 brains, numerous oval or rod-shaped aggregates were seen exclusively in the cytoplasm of Purkinje cells. These cytoplasmic inclusions were not ubiquitinated, which contrasts with the neuronal intra-nuclear inclusions of other CAG repeat/polyglutamine diseases. In cultured cells, formation of perinuclear aggregates of the channel protein and apoptotic cell death were seen when transfected with full-length CACNA1A coding an expanded polyglutamine tract. The present study indicates that the mechanism of neurodegeneration in SCA6 is associated with cytoplasmic aggregations of the [alpha]1A calcium channel protein caused by a small CAG repeat/polyglutamine expansion in CACNA1A.

Functional integrity of mitochondrial genomes in human platelets and autopsied brain tissues from elderly patients with Alzheimer's disease

To determine whether pathogenic mutations in mtDNA are involved in phenotypic expression of Alzheimer's disease (AD), the transfer of mtDNA from elderly patients with AD into mtDNA-less (rho0) HeLa cells was carried out by fusion of platelets or synaptosomal fractions of autopsied brain tissues with rho0 HeLa cells. The results showed that mtDNA in postmortem brain tissue survives for a long time without degradation and could be rescued in rho0 HeLa cells. Next, the cybrid clones repopulated with exogenously imported mtDNA from patients with AD were used for examination of respiratory enzyme activity and transfer of mtDNA with the pathogenic mutations that induce mitochondrial dysfunction. The presence of the mutated mtDNA was restricted to brain tissues and their cybrid clones that formed with synaptosomes as mtDNA donors, whereas no cybrid clones that isolated with platelets as mtDNA donors had detectable mutated mtDNA. However, biochemical analyses showed that all cybrid clones with mtDNA imported from platelets or brain tissues of patients with AD restored mitochondrial respiration activity to almost the same levels as those of cybrid clones with mtDNA from age-matched normal controls, suggesting functional integrity of mtDNA in both platelets and brain tissues of elderly patients with AD. These observations warrant the reassessment of the conventional concept that the accumulation of pathogenic mutations in mtDNA throughout the aging process is responsible for the decrease of mitochondrial respiration capacity with age and with the development of age-associated neurodegenerative diseases.

Amyloid-beta-protein isoforms in brain of subjects with PS1-linked, beta APP-linked and sporadic Alzheimer disease

To determine whether similar abnormalities of various soluble full-length and N-terminal truncated Abeta peptides occur in postmortem cerebral cortex of affected PS1 mutation carriers, we examined the amounts of two amyloid species ending at residue 40 or at residues 42(43) using sandwich ELISA systems. Our results indicate that PS1 mutations effect a dramatic accumulation in brain of the highly insoluble potentially neurotoxic long-tailed isoforms of the Abeta peptide such as Abeta1-42(43) and Abetax-42(43). This enhancing effect of PS1 mutation on Abetax-42(43) deposition was highly similar to that of a betaAPP mutation (Val717Ile) but the effects on Abetax-40 production were significantly different between these two causal genes. In contrast to previous studies of soluble Abeta in plasma and in supernatants from cultured fibroblasts of subjects with PS1 mutations, our studies also show that there is an increase in insoluble Abetax-40 peptides in brain of subjects with PS1 mutations.

Amyloid beta protein in plasma from patients with sporadic Alzheimer's disease

Fibrillar amyloid beta protein (A beta) deposition is increased in the brains of patients with Alzheimer's disease (AD), and is manifested as senile plaques (SPs) and congophilic angiopathy (CA). A beta 40 and A beta 42(43), two chief species of A beta, are documented in SPs and CA, as well as in cerebrospinal fluid (CSF) and cell culture media. A beta 42(43) is the major component of diffuse plaques, the earliest form of SPs. Thus, we hypothesized that determination of the amount of A beta 42(43) in CSF or plasma might provide a diagnostic laboratory test for AD. We measured amounts of different A beta species in plasma from 28 patients with sporadic probable AD, 40 age-matched neurologic patients without dementia and 25 age-matched normal controls using enzyme-linked immunosorbent assays (ELISAs). Plasma concentrations of A beta 1-40 and A beta 1-42(43) did not significantly differ among these groups. These findings suggest the unlikelihood that plasma A beta assays would be useful as a diagnostic tool for AD.

Calbindin-D 28k immunoreactivity in the cerebellum of spinocerebellar degeneration

We studied immunoreactivity for calbindin-D 28k (CaBP), an intracellular calcium-binding protein, in the cerebellum of control subjects and of patients with spinocerebellar degeneration (SCD) including sporadic olivopontocerebellar atrophy and familial cortical cerebellar atrophy. In the cerebellum, CaBP immunoreactivity was seen exclusively in the Purkinje cell in both SCD and control groups. However, the number of CaBP-immunoreactive Purkinje cells was significantly reduced in SCD. CaBP immunohistochemistry also disclosed abnormal morphological changes of Purkinje cells, which was not visualized on conventional strains or not clearly demonstrated on immunohistochemistry for neurofilaments. Moreover, reduced CaBP immunoreactivity was observed even in some remaining Purkinje cells of SCD suggesting that loss of CaBP precedes neuronal loss of Purkinje cell. We conclude that CaBP is a useful marker for Purkinje cell degeneration, and that reduced CaBP expression might have some association with the mechanism of the Purkinje cell degeneration in SCD.

Dose-dependent association of apolipoprotein E allele epsilon 4 with late-onset, sporadic Alzheimer's disease

We examined the apolipoprotein E (apo E) genotypes in 47 patients with late-onset sporadic Alzheimer's disease (mean age at onset +/- standard deviation, 72.2 +/- 6.4 years), 8 with late-onset familial Alzheimer's disease (75.5 +/- 5.1 years), 18 with early-onset sporadic Alzheimer's disease (52.8 +/- 4.7 years), and 10 with early-onset familial Alzheimer's disease (52.0 +/- 6.8 years) in Japan and compared them with genotypes in control subjects. In late-onset sporadic Alzheimer's disease, apo E-epsilon 4 frequency increased significantly (epsilon 4 frequency: 0.34 vs 0.095 in controls, p < 0.0001), and the odds ratio, which represents the strength of association between Alzheimer's disease and apo E-epsilon 4, markedly increased with increasing dose of apo E-epsilon 4 gene (3 [95% confidence interval, 2-6] in one dose; 43 [95% confidence interval, 12-154] in two doses). This study also suggested that apo E-epsilon 4 is associated with both late-onset (epsilon 4: 0.31) and early-onset familial Alzheimer's disease (epsilon 4: 0.35). In contrast, we found no association between apo E-epsilon 4 and early-onset sporadic Alzheimer's disease (epsilon 4: 0.08). These results indicate that the risk of developing late-onset sporadic Alzheimer's disease is markedly dependent on the dose of apo E-epsilon 4, while apo E-epsilon 4 does not appear to be a major risk factor for early-onset sporadic Alzheimer's disease.

Screening of the mis-sense mutation producing the 717Val-->Ile substitution in the amyloid precursor protein in Japanese familial and sporadic Alzheimer's disease

We investigated a C to T transition at base pair 2149 in the amyloid precursor protein gene in 41 Japanese cases of early-onset familial Alzheimer's disease (FAD), late-onset FAD and sporadic Alzheimer's disease (AD) by polymerase chain reaction and restriction enzyme polymorphism with BclI. Among 9 early-onset FAD patients derived from independent families, only one patient had the mis-sense mutation. Neither 5 patients with late-onset FAD nor 27 patients with sporadic AD had the mutation. Our result and the previous reports from Japan indicate that this type of mis-sense mutation is present in several cases of Japanese early-onset FAD. On the other hand, our data suggest that this mutation is not a common cause of Japanese early-onset FAD. Moreover, this mutation could be absent in late-onset FAD and sporadic AD in Japan. Because the mutation has been reported to be rare in Caucasian early-onset FAD and to be absent in Caucasian late-onset FAD and sporadic AD, the situation of this mutation in Alzheimer's disease may be common beyond the ethnic background.

Argentophilic intracytoplasmic inclusions in multiple system atrophy

Argentophilic intracytoplasmic glial inclusions were recently reported in olivo-ponto-cerebellar atrophy (OPCA). We examined the brains of 3 cases of OPCA [2 with striato-nigral degeneration (SND) and 1 without SND], 1 case of pure autonomic failure (PAF) without pathology of OPCA or SND, as well as 36 controls including 2 cases of Holmes' type cerebellar cortical atrophy and 2 cases of Joseph's disease. Although the inclusions were tubulin-positive, the immunoreactivity was different from that of the dendrites. Electron microscopically, the microtubular structures composing the inclusion were fuzzy with granular material. These findings may indicate that the microtubules composing the inclusions are modified. Inclusion-bearing cells appeared to be oligodendrocytes while many of them had larger and lighter nuclei than those of normal-looking oligodendrocytes without the inclusions. The inclusions were widely distributed in a characteristic fashion beyond the typical lesions of OPCA, SND and PAF. The distribution pattern was essentially the same in the case of PAF and 3 cases of OPCA irrespective of the presence or absence of OPCA or SND lesions. In contrast, argentophilic inclusions were not observed in other types of spinocerebellar degeneration, in Holmes' type cerebellar cortical atrophy or in Joseph's disease. It is suggested, in line with other studies, that the inclusion may be specific to OPCA and related disorders which include PAF and a useful marker to distinguish OPCA from other neurodegenerative diseases.