Cerebrospinal Fluid and Plasma Biomarkers in Neurodegenerative Diseases.

Cerebrospinal fluid (CSF) amyloid-ß (Aß)42 and tau are biomarkers for Alzheimer's disease (AD); however, the effects of other neurodegenerative processes on these biomarkers remain unclear. We measured Aß40, Aß42, total tau, phosphorylated-tau, and α-synuclein in CSF and plasma using matched samples from various neurodegenerative diseases to expand our basic knowledge on these biomarkers and their practical applications. A total of 213 CSF and 183 plasma samples were analyzed from cognitively unimpaired subjects, and patients with Alzheimer's disease dementia (ADD), mild cognitive impairment (MCI), non-AD dementias, and other neurological diseases. The CSF/plasma ratios of Aß40 and Aß42 were approximately 25:1. Aß40/42 ratios in CSF and plasma were both 10:1. The CSF total tau/P181tau ratio was 6:1. The CSF/plasma α-synuclein ratio was 1:65. Significantly decreased Aß42 levels and an increased Aß40/42 ratio in CSF in ADD/MCI suggested that these relationships were specifically altered in AD. Increased total tau levels in ADD/MCI, encephalopathy, and multiple system atrophy, and increased P181tau in ADD/MCI indicated that these biomarkers corresponded to neurodegeneration and tauopathy, respectively. Although CSF α-synuclein levels were increased in ADD/MCI, there was no merit in measuring α-synuclein in CSF or plasma as a biomarker. The combination of biomarkers by the Aß40/42 ratio×p181tau reflected specific changes due to the AD pathology in ADD/MCI. Thus, CSF Aß40, Aß42, p181tau, and tau were identified as biomarkers for aggregated Aß associated state (A), aggregated tau associated state (T), and neurodegeneration state (N) pathologies in AD based on the NIA-AA criteria. Overlaps in these biomarkers need to be considered in clinical practice for differential diagnoses of neurodegenerative diseases.

Disease modifying therapies for Alzheimer's disease targeting Aß oligomers: implications for therapeutic mechanisms.

Several lines of evidence indicate that amyloid ß (Aß), particularly Aß oligomers (AßOs), plays a causative role in Alzheimer's disease. However, the mechanisms underlying the action of an anti-AßO antibody to clarify the toxic action of AßOs remain elusive. Here, we showed that the anti-AßO antibody (monoclonal 72D9) can modify the Aß aggregation pathway. We also found that 72D9 directly sequesters both extracellular and intraneuronal AßOs in a nontoxic state. Thus, therapeutic intervention targeting AßOs is a promising strategy for neuronal protection in Alzheimer's disease.

An unusual case of elderly-onset cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) with multiple cerebrovascular risk factors.

Here we report a female patient with elderly-onset cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). At age 71, she developed gait disturbance, followed by memory disturbance 1 year later. She had been treated for hypertension and diabetes mellitus for 19 years. There apparently was low penetrance of disease. Magnetic resonance imaging (MRI) findings showed typical features of CADASIL, and the R607C mutation was detected in exon 11 in NOTCH3. This case strongly indicates that CADASIL should be considered when typical findings are observed on MRI even in cases of elderly onset with multiple cerebrovascular risk factors.

Factors responsible for neurofibrillary tangles and neuronal cell losses in tauopathy.

TgTauP301L mice that overexpress the mutant human tauP301L present in FTDP-17 reproduce neurofibrillary tangles (NFTs), neuronal cell losses, memory disturbance, and substantial phenotypic variation. To demonstrate factors responsible for NFT formation and neuronal cell losses, sets of TgTauP301L for comparison with or without NFTs and neuronal cell losses were studied with oligonucleotide microarrays. Gene expressions were altered in biological pathways, including oxidative stress, apoptosis, mitochondrial fatty acid betaoxidation, inflammatory response pathway, and complement and coagulation cascade pathways. Among 24 altered genes, increased levels of apolipoprotein D (ApoD) and neuronal PAS domain protein 4 (Npas4) and decreased levels of doublecortin (DCX) and potassium channel, voltage-gated, shaker-related subfamily, ß member 1 (Kcnab1) were found in the TgTauP301L with NFTs and neuronal cell losses, Alzheimer's brains, and tauopathy brains. Thus, many biological pathways and novel molecules are associated with NFT formation and neuronal cell losses in tauopathy brains.

Prevalence of autosomal dominant cerebellar ataxia in Aomori, the northernmost prefecture of Honshu, Japan.

OBJECTIVE: The frequency of autosomal dominant cerebellar ataxia (ADCA) varies between different regions of Japan. This is the first report on the prevalence of ADCA subtypes in Aomori, Japan. METHODS AND PATIENTS: Sixty-five familial spinocerebellar ataxia (SCA) patients and 15 sporadic SCA patients were genetically examined. For only the SCA2 patients (n = 8), the magnetic resonance imaging (MRI) data were analyzed in detail. RESULTS: Spinocerebellar ataxia (SCA) type 6 was often observed (77.7% of cases), with SCA2 (10.6% of cases) being the next most common form. In contrast, only one of the eighty patients had SCA1. Among the 15 sporadic SCA patients, genetic mutations for SCA2, SCA6, SCA17, and SCA31 were identified, indicating that ADCAs should be considered in sporadic cases of ataxia. Furthermore, in SCA2 cases, brainstem atrophy, pontine midline linear hyperintensity, and atrophy of the frontal lobes were frequently observed using MRI. CONCLUSION: The present data indicate that the prevalence of ADCA in Aomori differs from other prefectures in the Tohoku District. MRI findings are very similar between SCA2 and multiple system atrophy (MSA), and thus care must be taken to prevent the misdiagnosis of sporadic SCA2 as MSA.

Amyloid ß accelerates phosphorylation of tau and neurofibrillary tangle formation in an amyloid precursor protein and tau double-transgenic mouse model.

In Alzheimer's disease, Aß deposits are considered the initial cardinal events that induce tauopathy secondarily. However, the relationship between Aß amyloidosis and tauopathy has not been determined in detail. We produced double transgenic mice, 2×TgTau(+/-) APP(+/-) , by mating Tg2576 mice that exhibit Aß amyloidosis and TgTauP301L mice that show tauopathy, and statistically analyzed the effect of Aß accumulation on tauopathy. There was no significant difference in theprogression of Aß accumulation among 2×TgTau(+/-) APP(+/-) and 1×TgTau(-/-) APP(+/-) , and tau accumulation among 2×TgTau(+/-) APP(+/-) and 1×Tg Tau(+/-) APP(-/-) . The appearance rates of phosphorylated tau developing in neurons and processes were significantly accelerated in 2×TgTau(+/-) APP(+/-) mice compared with those in 1×TgTau(+/-) APP(-/-) mice at 23 months of age. Accumulation of phosphorylated and confomationally altered tau and GSK3ß in neuronal processes was accelerated in the white matter in 2×TgTau(+/-) APP(+/-) . The level of phosphorylated tau in the sarkosyl-insoluble fraction was increased in 2×TgTau(+/-) APP(+/-) brains compared with that in 1×TgTau(+/-) APP(-/-) brains. Thus, Aß amyloid partially enhances tauopathy through accumulation of insoluble, phosphorylated, and conformationally changed tau in neuronal cytoplasm and processes in the late stage.

Quantification of cystatin C in cerebrospinal fluid from various neurological disorders and correlation with G73A polymorphism in CST3.

Cystatin C (CC) is a cysteine protease inhibitor abundantly expressed in the central nervous system. Bunina bodies, small eosinophilic intraneuronal inclusions, are stain positive for CC and are the most specific histological hallmark of amyotrophic lateral sclerosis (ALS). In this study, employing a latex turbidimetric immunoassay, levels of CC in cerebrospinal fluid (CSF) were quantified in 130 age-matched individuals with either a neurological disorder [ALS, Alzheimer's disease (AD), Parkinson's disease (PD), tauopathy (TP), multiple system atrophy (MSA), chronic inflammatory demyelinating polyneuropathy (CIDP)] or no known neurological condition (normal control, NC). The CC level in CSF was found to be correlated with the age during the investigation but not the protein concentration. There was no difference in CC levels between NC and ALS or CIDP cases, whereas CC levels were significantly lower in MSA compared with NC. Of the 130 cases, 96 were genotyped, and G/A or A/A polymorphism at +73 within the CST3 gene was found in 28 individuals. The CC level was significantly lower in the combined group of G/A and A/A genotypes compared with G/G. The present data demonstrate that the level of CC in CSF should not be considered as a biomarker of ALS, but there is a correlation between CC levels and the CST3 genotype.

An unusual case of chronic relapsing tetanus associated with mandibular osteomyelitis.

A 55-year-old man underwent radiation therapy due to malignant lymphoma of the neck. Eight years after the therapy he developed tetanus. It appears that the radiation therapy resulted in mandibular necrosis, and that this lesion may have been the infectious focus of tetanus. Treatment with penicillin G was very effective in the acute stage, and chronic administration of metronidazole prevented relapse of the disease. However in spite of injections of tetanus toxoid, symptoms of tetanus returned when the administration of metronidazole was discontinued because the infectious focus could not be completely removed. This is the first report of chronic relapsing tetanus associated with radiation-induced mandibular osteomyelitis, and demonstrates that tetanus can occur due to mandibular focus but the chronic administration of metronidazole can prevent relapse.

A small trinucleotide expansion in the TBP gene gives rise to a sporadic case of SCA17 with abnormal putaminal findings on MRI.

A Japanese woman developed gait disturbances at 25 years of age, and subsequently underwent gradual changes in her personality. By the age of 42, she showed clear signs of dementia and cerebellar ataxia, and displayed behavioral abnormalities, choreic movements and hyperreflexia. The findings of MRI not only showed cerebellar and cerebral atrophy, but also revealed putaminal rim hyperintensity on T2-weighted images. We identified a heterozygously expanded CAG/CAA repeat (45/36) within the TATA-binding protein gene, leading to a diagnosis of SCA17. These results show that a 45 CAG/CAA repeat is pathological, giving rise to early-onset SCA17.