Diagnostic criteria for adult-onset leukoencephalopathy with axonal spheroids and pigmented glia due to CSF1R mutation.

BACKGROUND AND PURPOSE: To establish and validate diagnostic criteria for adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) due to colony-stimulating factor 1 receptor (CSF1R) mutation. METHODS: We developed diagnostic criteria for ALSP based on a recent analysis of the clinical characteristics of ALSP. These criteria provide 'probable' and 'possible' designations for patients who do not have a genetic diagnosis. To verify its sensitivity and specificity, we retrospectively applied our criteria to 83 ALSP cases who had CSF1R mutations (24 of these were analyzed at our institutions and the others were identified from the literature), 53 cases who had CSF1R mutation-negative leukoencephalopathies and 32 cases who had cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) with NOTCH3 mutations. RESULTS: Among the CSF1R mutation-positive cases, 50 cases (60%) were diagnosed as 'probable' and 32 (39%) were diagnosed as 'possible,' leading to a sensitivity of 99% if calculated as a ratio of the combined number of cases who fulfilled 'probable' or 'possible' to the total number of cases. With regard to specificity, 22 cases (42%) with mutation-negative leukoencephalopathies and 28 (88%) with CADASIL were correctly excluded using these criteria. CONCLUSIONS: These diagnostic criteria are very sensitive for diagnosing ALSP with sufficient specificity for differentiation from CADASIL and moderate specificity for other leukoencephalopathies. Our results suggest that these criteria are useful for the clinical diagnosis of ALSP.

Clinical and genetic characterization of adult-onset leukoencephalopathy with axonal spheroids and pigmented glia associated with CSF1R mutation.

BACKGROUND AND PURPOSE: The clinical characteristics of colony stimulating factor 1 receptor (CSF1R) related adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) have been only partially elucidated. METHODS: Clinical data from CSF1R mutation carriers who had been seen at our institutions or reported elsewhere were collected and analysed using a specific investigation sheet to standardize the data. RESULTS: In all, 122 cases from 90 families with CSF1R mutations were identified. The mean age of onset was 43 years (range 18-78 years), the mean age at death was 53 years (range 23-84 years) and the mean disease duration was 6.8 years (range 1-29 years). Women had a significantly younger age of onset than men (40 vs. 47 years, P = 0.0006, 95% confidence interval 3.158-11.177). There was an age-dependent penetrance that was significantly different between the sexes (P = 0.0013). Motor dysfunctions were the most frequent initial symptom in women whose diseases began in their 20s. Thinning of the corpus callosum, abnormal signalling in pyramidal tracts, diffusion-restricted lesions and calcifications in the white matter were characteristic imaging findings of ALSP. The calcifications were more frequently reported in our case series than in the literature (54% vs. 3%). Seventy-nine per cent of the mutations were located in the distal part of the tyrosine kinase domain of CSF1R (102 cases). There were no apparent phenotype-genotype correlations. CONCLUSIONS: The characteristics of ALSP were clarified. The phenotype of ALSP caused by CSF1R mutations is affected by sex.

Nicastrin binds to membrane-tethered Notch.

The presenilins and nicastrin, a type 1 transmembrane glycoprotein, form high molecular weight complexes that are involved in cleaving the beta-amyloid precursor protein (betaAPP) and Notch in their transmembrane domains. The former process (termed gamma-secretase cleavage) generates amyloid beta-peptide (Abeta), which is involved in the pathogenesis of Alzheimer's disease. The latter process (termed S3-site cleavage) generates Notch intracellular domain (NICD), which is involved in intercellular signalling. Nicastrin binds both full-length betaAPP and the substrates of gamma-secretase (C99- and C83-betaAPP fragments), and modulates the activity of gamma-secretase. Although absence of the Caenorhabditis elegans nicastrin homologue (aph-2) is known to cause an embryonic-lethal glp-1 phenotype, the role of nicastrin in this process has not been explored. Here we report that nicastrin binds to membrane-tethered forms of Notch (substrates for S3-site cleavage of Notch), and that, although mutations in the conserved 312-369 domain of nicastrin strongly modulate gamma-secretase, they only weakly modulate the S3-site cleavage of Notch. Thus, nicastrin has a similar role in processing Notch and betaAPP, but the 312-369 domain may have differential effects on these activities. In addition, we report that the Notch and betaAPP pathways do not significantly compete with each other.

Presenilin mutations associated with Alzheimer disease cause defective intracellular trafficking of beta-catenin, a component of the presenilin protein complex.

The presenilin proteins are components of high-molecular-weight protein complexes in the endoplasmic reticulum and Golgi apparatus that also contain beta-catenin. We report here that presenilin mutations associated with familial Alzheimer disease (but not the non-pathogenic Glu318Gly polymorphism) alter the intracellular trafficking of beta-catenin after activation of the Wnt/beta-catenin signal transduction pathway. As with their effect on betaAPP processing, the effect of PS1 mutations on trafficking of beta-catenin arises from a dominant 'gain of aberrant function' activity. These results indicate that mistrafficking of selected presenilin ligands is a candidate mechanism for the genesis of Alzheimer disease associated with presenilin mutations, and that dysfunction in the presenilin-beta-catenin protein complexes is central to this process.

Autosomal recessive hereditary spastic paraplegia with thin corpus callosum: a novel mutation in the SPG11 gene and further evidence for genetic heterogeneity.

BACKGROUND AND PURPOSE: Autosomal Recessive Hereditary Spastic Paraplegia with Thin Corpus Callosum (AR-HSPTCC) is a clinically and genetically heterogeneous complicated form of spastic paraplegia. Two AR-HSPTCC loci have been assigned to chromosome 15q13-15 (SPG11) and chromosome 8p12-p11.21 respectively. Mutations in the SPG11 gene, encoding the spatacsin protein, have been found in the majority of SPG11 families. In this study, involvement of the SPG11 or 8p12-p11.21 loci was investigated in five Italian families, of which four consanguineous. METHODS: Families were tested for linkage to the SPG11 or 8p12-p11.21 loci and the SPG11 gene was screened in all the affected individuals. RESULTS: Linkage was excluded in the four consanguineous families. In the only SPG11-linked family the same homozygous haplotype 4.2 cM across the SPG11 locus was shared by all the three affected siblings. A novel c.2608A>G mutation predicted to affect the splicing was found in exon 14 of the SPG11 gene. DISCUSSION: This collection of families contributes to highlight the intra and inter locus heterogeneity in AR-HSPTCC, already remarked in previous reports. In particular, it confirms heterogeneity amongst Italian families and reports a new mutation predicted to affect splicing in the spatacsin gene.

Mutation of conserved aspartates affect maturation of presenilin 1 and presenilin 2 complexes.

Presenilin (PS1 and PS2) holoproteins are transiently incorporated into low molecular weight (MW) complexes. During subsequent incorporation into a higher MW complex, they undergo endoproteolysis to generate stable N- and C-terminal fragments (NTF/CTF). Mutation of either of two conserved aspartate residues in transmembrane domains inhibits both presenilin-endoproteolysis and the proteolytic processing of APP and Notch. We show that aspartate-mutant holoprotein presenilins are not incorporated into the high molecular weight, NTF/CTF-containing complexes. Aspartate-mutant presenilin holoproteins also preclude entry of endogenous wild-type PS1/PS2 into the high molecular weight complexes, but do not affect the incorporation of wild-type holoproteins into lower molecular weight holoprotein complexes. These data suggest that the loss-of-function aspartate-mutants cause altered PS complex maturation, and argue that the functional presenilin moieties are contained in the high molecular weight presenilin NTF/CTF-containing complexes.

Structure and organization of the gene encoding human dopamine transporter.

The human dopamine transporter (hDAT) is a member of the subfamily of monoamine transporters which show a common topological structure and possess significant amino acid sequence homology. We isolated and characterized the hDAT gene including about 1 kb of 5'-flanking region. The hDAT gene spans over 64 kb, consisting of 15 exons separated by 14 introns. The intron-exon structure of the hDAT gene is most similar to that of the human noradrenaline transporter (hNAT) gene. Promoter sequence analysis demonstrated a 'TATA'-less, 'CAT'-less and G+C-rich structure. Two E box and several Sp-1-binding sites exist in the promoter region. These structural features are similar to that of the human D1A dopamine receptor gene and the human monoamine oxidase A gene. The transcription start site was determined by both 5'-RACE and RNase protection assay. We determined the 5' end of the mRNA by identifying the 5'-terminal cap-G residue in 5'-RACE and RNase protection assay.

Organization of the human orphan nuclear receptor Nurr1 gene.

Recent reports have revealed that Nurr1 (also known as NOT/TINUR/RNR-1/HZF-3), a member of the steroid/thyroid hormone nuclear receptor superfamily, is predominantly expressed in the midbrain; substantia nigra (SN) and ventral tegmental area (VTA). Nurr1 null mice are born lethal, lacking the midbrain dopamine (DA) neurons, suggesting that Nurr1 is essential for the development and differentiation of midbrain DA neurons. Human Nurr1 gene has been mapped on chromosome 2q22-23, which is reported to associate weakly with schizophrenia. We cloned and sequenced the human Nurr1 gene, which is approximately 8.3kb long, consisting of eight exons and seven introns. Comparisons of the human Nurr1 with the mouse Nurr1, mouse Nur77 and human NOR-1 revealed that their genomic structures were highly conserved. The 5'-flanking region of the human Nurr1 included three transcriptional regulatory elements, cAMP-response element (CRE), CArG-like element and Sp-1 site, which were surrounded by CpG island, and showed a strong homology with the mouse Nurr1. We performed a primer extension analysis using mRNA from HeLa S3 cells stimulated with phorbol 12-myristate 13-acetate (PMA), Ca2+ ionophore A23187 and cycloheximide (CHX) in order to induce the Nurr1 mRNA expression, and determined one transcription initiation site within CRE. The transient transfection assay indicates that the regulatory elements in the 5'-flanking region are robust for mitogen-induced expression of the human Nurr1. Further analysis of the polymorphism of the human Nurr1 gene may reveal the association with diseases characterized by changes of the DA system, such as Parkinson's disease and schizophrenia.

A new mitochondrial DNA mutation associated with mitochondrial myopathy: tRNA(Leu)(UUR) 3254C-to-G.

We investigated a patient with mitochondrial myopathy accompanied by cardiomyopathy. Molecular analysis disclosed a C-to-G substitution at nucleotide position 3254 of the mitochondrial tRNA(Leu)(UUR). Pedigree analysis revealed that this mutation was inherited maternally. Mutation C3254G may also be a candidate for genetic defects in mitochondrial myopathy.

Familial frontotemporal dementia with ubiquitin-positive, tau-negative inclusions.

OBJECTIVE: To describe the clinical features, neuropathology, and genetic studies in a family with autosomal dominant frontotemporal dementia (FTD). BACKGROUND: Clinical Pick's disease, or FTD with parkinsonism, has been described in several families linked to chromosome 17 (FTDP-17). Most of these have shown tau protein mutations. The clinical and pathologic variations in these families resemble the spectrum of sporadic FTD or "Pick complex." METHODS: Clinical and behavioral analysis of the affected members with extensive histochemical and neuropathologic description of three cases, genetic analysis of three clinically affected members and seven at risk members to assess linkage to chromosome 17, and sequencing of the tau gene in two patients were performed. RESULTS: The clinical pattern shows a highly stereotypic disinhibition dementia with late extrapyramidal features, progressive mutism, and terminal dysphagia in three generations of affected individuals. Neuropathology showed frontotemporal atrophy, and microscopically tau- and synuclein-negative and ubiquitin-positive neuronal inclusions, in the background of superficial cortical spongiosis, neuronal loss, and gliosis. Tau expression was restricted to oligodendroglia. All exons and surrounding introns of the tau gene were sequenced, and no mutation or disease-related polymorphisms were detected in either of two affected pedigree members. CONCLUSION: This family with autosomal dominant frontotemporal dementia (FTD) shows no tau expression in neurons. The ubiquitin-positive, tau-negative inclusions have been described before in FTD with and without motor neuron disease, but not in a familial form. The clinical and some pathologic features are similar to those of several of the families included in descriptions of FTD with parkinsonism linked to chromosome 17, but the linkage to tau has been excluded. The defect in this family, however, could be functionally related to tau mutations.

Clinical and genetic study of a large Italian family linked to SPG12 locus.

BACKGROUND: Seven loci for autosomal dominant hereditary spastic paraplegia (ADHSP) have been mapped. To date, two families of SPG12 (chromosome 19q13) have been analyzed; however, there is not enough clinical information on SPG12 to establish locus-phenotype correlations. METHODS: The authors studied 60 individuals from a large Italian family with ADHSP, in which 16 members in four generations were affected. They performed genetic linkage analysis with DNA markers from currently known ADHSP loci. After database searching, one candidate gene for SPG12 was analyzed by sequencing. RESULTS: The patients in this family showed an early onset and rapid progression of symptoms, resulting in severe disability, with a large proportion of affected members requiring use of a wheelchair. By age 16, most patients had sensory disturbance. Evidence for linkage to the SPG12 locus was obtained. Obligate recombination events observed in this family have narrowed the SPG12 locus from the 16.1 cM to 11.3 cM region between markers D19S416 and D19S412. In combination with previous genetic studies, the SPG12 locus was further narrowed to the 3.3 cM region between D19S416 and D19S220. A homologue of the AAA (ATPases associated with a variety of cellular activities) protein family, proteasome 26S subunit ATPase mapped near D19S220, was excluded by sequencing. CONCLUSIONS: This study refined the SPG12 region between D19S416 and D19S220 and revealed several clinical characteristics-early onset, rapid progression, and involvement of sensory disturbance-that may be unique to SPG12. Suggestive evidence of genetic anticipation was obtained, but should be confirmed in other SPG12 families.

Mutation of the conserved N-terminal cysteine (Cys92) of human presenilin 1 causes increased A beta42 secretion in mammalian cells but impaired Notch/lin-12 signalling in C. elegans.

The presenilin proteins are involved in the proteolytic processing of transmembrane proteins such as Notch/lin-12 and the beta-amyloid precursor protein (betaAPP). Mutation of a conserved cysteine (Cys60Ser) in the C. elegans presenilin sel-12 has a loss-of-function effect on Notch/lin-12 processing similar to that of null mutations in sel-12. In contrast, in mammalian cells, most missense mutations increase gamma-secretase cleavage of betaAPP. We report here that mutation of this conserved cysteine (Cys92Ser) in human presenilin 1 confers a loss-of-function effect in C. elegans, but causes increased A beta42 secretion in mammalian cells. These data suggest that the role of presenilins in Notch/lin-12 signalling and betaAPP processing are either separately regulated activities or independent activities of the presenilins.

A large Calabrian kindred segregating frontotemporal dementia.

Frontotemporal dementia (FTD) displays significant neuropathological and genetic heterogeneity among and within affected families. An early diagnosis is often difficult because cognitive symptoms are manifest only at a late stage of the disease. We have been studying a large pedigree segregating frontotemporal dementia (FTD) to which belong 34 identified affected persons, 11 of whom were personally examined. The kindred has been genealogically reconstructed; all FTD patients have been linked to the same ancestors who lived in the early 18(th) century (11 generations before the present one). Autosomal dominant transmission was evident. Clinical features were uniform within the kindred and met the Lund-Manchester criteria. Personality changes with absence of insight, lack of empathy and of social awareness manifested up to 5 years before medical advice was sought. Loss of fluency was the earliest neuropsychological sign, in the absence of memory, orientation and praxis deficits, which evolved late, together with hyperorality. Akinesia was observed early, rigidity appeared late, tremor was absent. Two patients showed myoclonus late in their evolution. No ALS signs were observed in this kindred. Mutations of the MAPt gene, coding for the Tau protein, were not detected in affected family members. Linkage studies excluded chromosomes 3 and 9 and gave indeterminate results that were model dependent for chromosome 17.

Absence of linkage between familial amyotrophic lateral sclerosis and copper chaperone for the superoxide dismutase gene locus in two Italian pedigrees.

We investigated the segregation of the copper chaperone for the superoxide dismutase (CCS) gene in two Italian families with amyotrophic lateral sclerosis lacking the mutations in superoxide dismutase 1 gene. We analyzed a total of 56 individuals; six people were affected. Diagnoses were made using the El Escorial criteria. The results of our study provide no evidence of a linkage between markers flanking the CCS gene and familial amyotrophic lateral sclerosis (FALS) in these FALS kindreds.

Absence of association between Alzheimer disease and the -491 regulatory region polymorphism of APOE.

A novel polymorphism (-491 A/T) within the regulatory region on the apolipoprotein E gene has recently been reported to be associated with risk for Alzheimer disease (AD). To test this association in an independent data set, we have examined this polymorphism in a sample of 88 well-characterized AD cases and compared the allele frequency and genotype frequencies for this polymorphism with those observed in 112 cognitively normal subjects drawn from the same ethnic group. These results suggest that in the current data set at least, the -491 A/T polymorphism is not associated with risk for AD, but may be in partial linkage disequilibrium with the APOE epsilon2/epsilon3/epsilon4 polymorphism.

No association between apolipoprotein E alleles and olivopontocerebellar atrophy.

Apolipoprotein E (apo E) epsilon4 is a risk factor for sporadic and late-onset familial Alzheimer's disease, but it is not well known whether the apo E is associated with spinocerebellar degeneration. We studied the frequency of apo E allele in 59 olivopontocerebellar atrophy (OPCA) patients, including 13 pathologically confirmed cases. The distribution of the apo E allele frequency did not differ between OPCA patients and controls. Apo E allele does not influence the development of OPCA.

Pleasant feeling from watching a comical video enhances free radical-scavenging capacity in human whole saliva.

OBJECTIVE: Free radicals have been implicated in aging, mutagenesis, inflammation and other pathological conditions. We conducted a study to clarify the relation between a pleasant feeling as a psychological eustress and free radical-scavenging capacity (FRSC) in saliva. METHODS: Saliva was collected from 27 healthy volunteers. FRSC before, during and after watching a cheerful comical video for 30 min was measured by using 1,1-diphenyl-2-picrylhydrazyl (DPPH). RESULTS: The median values of FRSC (micromol/ml) before, at 10 and 20 min during and after watching the video were 54.5, 66.8, 66.6 and 69.4, respectively. The FRSC values obtained after watching the video were significantly higher than those before watching it (P<.001). When the FRSC before watching was taken as 1, the value for the group that felt "Very good," "Good" or "Ordinary+Dull" while watching the video for 30 min was 1.38, 1.20 or 0.98, respectively (P<.01). CONCLUSION: Watching a comical video enhanced the FRSC in saliva; in addition, a pleasant feeling boosted it even more.

Effect of high pressure gaseous carbon dioxide on the germination of bacterial spores.

Effect of high pressure gaseous carbon dioxide treatment (HGCT) at 6.5 MPa, 35 degrees C on the germination of bacterial spores was investigated. Germination of bacterial spores was estimated by the decrease of heat tolerance. Approximately, 40% of Bacillus coagulans and 70% of Bacillus licheniformis were germinated by HGCT for 120 min at 35 degrees C, respectively. Germination was confirmed by phase contrast microscopy. The effect of hydrostatic pressure treatment (HPT) at 6.5 MPa, 35 degrees C on the germination of B. coagulans and B. licheniformis spores were also investigated. Spores did not germinate by HPT alone at 6.5 MPa for 120 min.

[Familial fronto-temporal dementia with brain stem ubiquitin-positive neuronal inclusions]. / Démence fronto-temporale familiale avec inclusions marquées par l'anti-ubiquitine dans le tronc cérébral.

INTRODUCTION: Fronto-temporal dementias (FTD) were described a century ago on the macroscopic basis of frontal and/or temporal lobe atrophy. Progress in neuropathology, immunohistochemistry, biochemistry and genetics has since shown that they are heterogeneous entities, encompassing many different diseases with similar clinical presentations. A few, such as tauopathies due to mutations of the gene coding for tau protein (MAPtau form a well-defined group. Definition and grouping of other types of FTD is still problematic. MATERIAL AND METHOD: We studied a family where the mother and 4/8 children were affected with FTD. Clinical presentation was typical of FTD. Onset was ill-defined with early (at age 40 years or less) personality changes. The clinical course was protracted (about 30 years). For a long period, the patients were able to live in the community in spite of obvious signs such as hyperorality and loss of verbal initiative; operative orientation as to place was preserved for a long time: a mute patient was still able to drive. Signs of extrapyramidal or motoneuron involvement were not observed. RESULTS: The genetic study failed to detect any mutation in MAPtau; the lod score for flanking markers was positive but not significant. Biochemical study showed no qualitative abnormality in tau protein. Neuropathological study of one affected subject showed brain atrophy (962 g), with elective frontal lobe involvement. Cortical nerve cell loss was more marked in superficial layers and in frontal areas; glia was inconspicuous; pseudolaminar spongiosis was present in the more severely affected zones. No argentophilic "Pick bodies" were seen; ubiquitin-positive, tau-negative round inclusions were present in the cytoplasm of fascia dentata neurones. "Tangles" were mostly restricted to the entorhinal cortex, partly correlated with tau immunoreactivity, but better with ubiquitin immunoreactivity. Large, ovoid or reniform, moderately dense, spongy, granular or filamentous argentophilic cytoplasmic nerve cell inclusions were observed. They were ubiquitin-positive, but did not react with other antibodies, particularly anti-tau. They were present in swollen nerve cells in the deeper cortical layers but were most conspicuous in the brain stem: in the magnocellular reticular nuclei (e.g. nucleus centralis pontis), in the pes pontis, in the inferior olive and in motor nuclei, especially in the trigeminal motor nucleus. They were not associated with nerve cell loss, atrophy nor pycnosis. Cerebellar relay nuclei neurones were swollen, and their cytoplasm contained argentophilic filaments. CONCLUSION: In our opinion, "ubiquitinopathy" would be non-specific and "Motor Neuron Disease-Inclusion Dementia" (MNDID) would not be satisfactory as a diagnosis for the present cases of FTD. Hopefully, progress in genetics may allow a causal, and thence definitive, classification.