Tescalcin is a potential target of class I histone deacetylase inhibitors in neurons.

Class I histone deacetylase (HDAC) inhibitors are believed to have positive effects on neurite outgrowth, synaptic plasticity, and neurogenesis in adult brain. However, the downstream molecular targets of class I HDAC inhibitors in neurons are not clear. Although class I HDAC inhibitors are thought to broadly promote transcription of many neuronal genes through enhancement of histone acetylation, the affected gene set may include unidentified genes that are essential for neuronal survival and function. To identify novel genes that are targets of class I HDAC inhibitors, we used a microarray to screen transcripts from neuronal cultures and evaluated changes in protein and mRNA expression following treatment with four HDAC inhibitors. We identified tescalcin (Tesc) as the most strongly up-regulated gene following treatment with class I HDAC inhibitors in neurons. Moreover, hippocampal neurons overexpressing TESC showed a greater than 5-fold increase in the total length of neurites and number of branch points compared with controls. These findings highlight a potentially important role for TESC in mediating the neuroprotective effect of class I HDAC inhibitors. TESC may also be involved in the development of brain and neurodegenerative diseases through epigenetic mechanisms.

Removal of ballistocardiogram artifacts from simultaneously recorded EEG and fMRI data using independent component analysis.

Simultaneous recording of electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) has been studied to identify areas related to EEG events. EEG data recorded in the magnetic resonance (MR) scanner with MR imaging is suffered from two specific artifacts, imaging artifact, and ballistocardiogram (BCG). In this paper, we focus on BCG. In preceding studies, average subtraction was often used for this purpose. However, average subtraction requires an assumption that BCG waveforms are precisely periodic, which seems unrealistic because BCG is a biomedical artifact. We propose the application of independent component analysis (ICA) with a postprocessing of high-pass filtering for the removal of BCG. With this approach, it is not necessary to assume that the BCG waveform is periodic. Empirically, we show that our proposed method removes BCG artifacts as well as does the average subtraction method. Power spectral density analysis of the two approaches shows that, with ICA, distortion of recovered EEG data is also as small as that associated with the average subtraction approach. We also propose a hypothesis for how head movement causes BCGs and show why ICA can remove BCG artifacts arising from this source.

Natural isolates of Brome mosaic virus with the ability to move from cell to cell independently of coat protein.

Brome mosaic virus (BMV) requires encapsidation-competent coat protein (CP) for cell-to-cell movement and the 3a movement protein (MP) is involved in determining the CP requirement for BMV movement. However, these conclusions have been drawn by using BMV strain M1 (BMV-M1) and a related strain. Here, the ability of the MPs of five other natural BMV strains to mediate the movement of BMV-M1 in the absence of CP was tested. The MP of BMV M2 strain (BMV-M2) efficiently mediated the movement of CP-deficient BMV-M1 and the MPs of two other strains functioned similarly to some extent. Furthermore, BMV-M2 itself moved between cells independently of CP, demonstrating that BMV-M1 and -M2 use different movement modes. Reassortment between CP-deficient BMV-M1 and -M2 showed the involvement of RNA3 in determining the CP requirement for cell-to-cell movement and the involvement of RNAs 1 and 2 in movement efficiency and symptom induction in the absence of CP. Spontaneous BMV MP mutants generated in planta that exhibited CP-independent movement were also isolated and analysed. Comparison of the nucleotide differences of the MP genes of BMV-M1, the natural strains and mutants capable of CP-independent movement, together with further mutational analysis of BMV-M1 MP, revealed that single amino acid differences at the C terminus of MP are sufficient to alter the requirement for CP in the movement of BMV-M1. Based on these findings, a possible virus strategy in which a movement mode is selected in plant viruses to optimize viral infectivity in plants is discussed.