Differences in splicing defects between the grey and white matter in myotonic dystrophy type 1 patients.

Myotonic dystrophy type 1 (DM1) is a multi-system disorder caused by CTG repeats in the myotonic dystrophy protein kinase (DMPK) gene. This leads to the sequestration of splicing factors such as muscleblind-like 1/2 (MBNL1/2) and aberrant splicing in the central nervous system. We investigated the splicing patterns of MBNL1/2 and genes controlled by MBNL2 in several regions of the brain and between the grey matter (GM) and white matter (WM) in DM1 patients using RT-PCR. Compared with amyotrophic lateral sclerosis (ALS, as disease controls), the percentage of spliced-in parameter (PSI) for most of the examined exons were significantly altered in most of the brain regions of DM1 patients, except for the cerebellum. The splicing of many genes was differently regulated between the GM and WM in both DM1 and ALS. In 7 out of the 15 examined splicing events, the level of PSI change between DM1 and ALS was significantly higher in the GM than in the WM. The differences in alternative splicing between the GM and WM may be related to the effect of DM1 on the WM of the brain.

[A case of muscle sarcoidosis with hypercalcemia, lower limb muscle strength and without bilateral hilar lymphadenopathy].

A 73-year-old man was hospitalized with complaints of general malaise, limb muscle weakness and weight loss progressing in 6 months. Ca, ACE, lysozyme, sIL-2R, vitamin 1.25 D was high in the blood test. Bilateral hilar lymphadenopathy on CT were not recognized, and CD4/CD8 ratio increased by bronchoalveolar lavage. In the 67Ga-citrate scintigraphy, accumulation was observed on the thigh and shoulder to the upper arm bilaterally. A muscle biopsy was performed from the right femoris muscle where the gadolinium contrast effect in the T1 weighted image was observed. As muscle biopsy revealed non-toxic epithelial cell granulomas, he was diagnosed as muscle sarcoidosis. Even if bilateral hilar lymphadenopathy is not observed, muscle sarcoidosis should be considered in patients developed with hypercalcemia and limb muscle weakness.

Muscleblind-like 1 knockout mice reveal novel splicing defects in the myotonic dystrophy brain.

Myotonic dystrophy type 1 (DM1) is a multi-systemic disorder caused by a CTG trinucleotide repeat expansion (CTG(exp)) in the DMPK gene. In skeletal muscle, nuclear sequestration of the alternative splicing factor muscleblind-like 1 (MBNL1) explains the majority of the alternative splicing defects observed in the HSA(LR) transgenic mouse model which expresses a pathogenic range CTG(exp). In the present study, we addressed the possibility that MBNL1 sequestration by CUG(exp) RNA also contributes to splicing defects in the mammalian brain. We examined RNA from the brains of homozygous Mbnl1(ΔE3/ΔE3) knockout mice using splicing-sensitive microarrays. We used RT-PCR to validate a subset of alternative cassette exons identified by microarray analysis with brain tissues from Mbnl1(ΔE3/ΔE3) knockout mice and post-mortem DM1 patients. Surprisingly, splicing-sensitive microarray analysis of Mbnl1(ΔE3/ΔE3) brains yielded only 14 candidates for mis-spliced exons. While we confirmed that several of these splicing events are perturbed in both Mbnl1 knockout and DM1 brains, the extent of splicing mis-regulation in the mouse model was significantly less than observed in DM1. Additionally, several alternative exons, including Grin1 exon 4, App exon 7 and Mapt exons 3 and 9, which have previously been reported to be aberrantly spliced in human DM1 brain, were spliced normally in the Mbnl1 knockout brain. The sequestration of MBNL1 by CUG(exp) RNA results in some of the aberrant splicing events in the DM1 brain. However, we conclude that other factors, possibly other MBNL proteins, likely contribute to splicing mis-regulation in the DM1 brain.

Correlation of subthalamic nuclei T2 relaxation times with neuropsychological symptoms in patients with Parkinson's disease.

The subthalamic nucleus (STN) is a frequent target of deep brain stimulation (DBS), which is used to treat patients with advanced Parkinson's disease (PD). However, few studies have assessed the relationship between the STN and the clinical characteristics of PD patients. We identified the STN of 17 PD patients and 7 control subjects using coronal Short TI Inversion Recovery (STIR) magnetic resonance imaging (MRI) and estimated the T2 relaxation time (T2) of the STN on the subsequent coronal images that were acquired from T2-weighted MRI. The relationships between the STN T2 measurements and the PD patients' age, disease duration, laterality, and clinical scores were examined. STN T2 measurements tended to be lower in PD patients than in controls, although the difference was not significant. STN T2 measurements were significantly and inversely correlated (p=0.03) with scores on the Unified Parkinson's Disease Rating Scale (UPDRS) part 1, which was applied to evaluate the mentation, behavior, and mood of PD patients. However, no significant correlations were found between the STN T2 measurements and the patients' age, disease duration, laterality, or motor clinical scores. These results suggest that degeneration of the STN in PD patients may contribute to their neuropsychological symptoms.

Decreased chloride levels of cerebrospinal fluid in patients with amyotrophic lateral sclerosis.

Recent studies have suggested that the elevation of intracellular chloride contributes to excitotoxic cell death in motor neuron and can be related to the pathogenesis of amyotrophic lateral sclerosis (ALS). We investigated whether chloride levels in cerebrospinal fluid (CSF) and serum were lower in ALS patients than in control patients with other neurological diseases (OND). We also examined the relationship between chloride levels and clinical ALS phenotypes. We measured chloride levels (CSF and serum) in 27 ALS patients and 33 age- and gender-matched OND controls admitted to our hospital for diagnosis. The CSF chloride levels were lower in ALS patients (117 [range 102-130] mmol/L) than in OND controls (126 [range 114-134] mmol/L) (P<0.0001). However, no significant difference was found in their serum chloride levels (P>0.05). There was no significant difference in CSF chloride levels among the sub-groups of ALS patients classified according to their age, gender, duration of illness, clinical state and type of onset (P>0.05). CSF chloride levels already significantly decreased in ALS patients at the time of diagnosis. We conclude that the elevation of intracellular chloride would cause the reduction of chloride in CSF and be related to the pathogenesis of ALS.