Novel mutation in optineurin causing aggressive ALS+/-frontotemporal dementia.

OBJECTIVE: Mutations in optineurin (OPTN) have been identified in familial and sporadic amyotrophic lateral sclerosis (ALS). We screened a cohort of Chinese patients for mutations in optineurin. We also performed an extensive literatures review of all mutations in optineurin identified previously to detect genotype-phenotype associations. METHODS: All 16 exons of the OPTN gene in a cohort of 15 familial ALS indexes and 275 sporadic ALS patients of Chinese origin were sequenced by targeted next generation sequencing. RESULTS: Two known heterozygous missense mutations in the OPTN, c.1481T> G (p.L494W), and c.1546G> C (p.E516Q), as well as one novel heterozygous missense mutation c.1690G> C (p.D564H) were each detected in one sporadic ALS patient. The patient carrying the p.E516Q mutation developed clinical features of ALS-frontotemporal dementia (FTD) and the patient carrying the p.D564H mutation showed a phenotype of ALS. They both had an aggressive course, with a survival of 18 and 14 months respectively. Literature review showed that the clinical phenotypes in OPTN mutated ALS were not homogeneous, although some individuals showed a relatively slow progression and a long duration, some mutations carriers developed an aggressive progression and a short survival. INTERPRETATION: OPTN mutations contribute to ALS in Chinese population and account for 0.8% of sporadic ALS patients and 1.5% of familial ALS in the pooled Chinese ALS cohorts. Mutations in optineurin can cause aggressive ALS+/-FTD.

A novel VRK1 mutation associated with recessive distal hereditary motor neuropathy.

Vaccinia-related kinase 1 (VRK1) mutations can cause motor phenotypes including axonal sensorimotor neuropathy, distal hereditary motor neuropathy (dHMN), spinal muscular atrophy, and amyotrophic lateral sclerosis. Here, we identify a novel homozygous VRK1 p.W375X mutation causing recessive dHMN. The proband presented with juvenile onset of weakness in the distal lower extremities, slowly progressing to the distal upper limbs, with bilateral pes cavus and no upper motor or sensory neuron involvement. Nerve conduction studies showed a pure motor axonal neuropathy. Our findings extend the ethnic distribution of VRK1 mutations, indicating that these mutations should be included in genetic diagnostic testing for dHMN.

An adult case of multiphasic disseminated encephalomyelitis manifesting with optic neuritis.

A 25-year-old woman presented with a fever, headache, vomiting and somnolence. Cranial magnetic resonance imaging (MRI) showed multiple lesions in the cerebellum, brainstem, cerebral cortex and subcortex. Oligoclonal bands were positive in the cerebral spinal fluid (CSF). She experienced a good recovery after steroid treatment. Four months later, she developed right vision loss. Repeated MRI showed multiple cranial lesions different from those involved in the first attack in both size and distribution. An abnormal high signal was also observed in the front and intraorbital regions of the right optic nerve. The patient's vision progressively improved, and she obtained a full recovery following the administration of steroids. A diagnosis of multiphasic disseminated encephalomyelitis manifesting with optic neuritis was made.

Neuroprotective effects of new protein kinase C activator TPPB against Aß25₋35 induced neurotoxicity in PC12 cells.

Alzheimer's disease (AD) is pathologically characterized by presence of senile plaques in the hippocampus, which are composed mainly of extracellular deposition of a polypeptide known as the beta amyloid, the Aß. It has been demonstrated on numerous occasions that it was the deposition and aggregation of this Aß peptide that cause neuronal dysfunction and even finally, the dementia. Lowering the deposition of Aß or decreasing its neurotoxicity has long been one of the purposes of AD therapy. In previous study, we reported that protein kinase C (PKC) activator TPPB could regulate APP processing by increasing α-secretase activity. In this study we further investigated the potential neuroprotective effect of TPPB against Aß(25-35)-induced neurotoxicity in PC12 cells. The results indicated that TPPB at concentration of 1 µM could antagonize Aß(25-35) induced cell damage as evidenced by MTT assays, LDH release and by morphological changes. Furthermore, the neuroprotection in cell viability can be blocked by inhibitors of PKC, Akt and MAPK. The experiment also indicated that TPPB could increase the phosphorylation of Akt, PKC, MARCKS and MAPK, which were inhibited by Aß(25-35) treatment. Finally, TPPB inhibited the activation of caspase-3 induced by Aß(25-35). Taken together, the experiment here implies that TPPB has a role against Aß(25-35)-induced neurotoxicity in PC12 cells and may suggest its therapeutic potential in AD.