Molecular cloning of the m-Golsyn gene and its expression in the mouse brain

Sex- and tissue-specific effects of binge-level prenatal alcohol consumption on DNA methylation at birth

Background: Binge-level prenatal alcohol exposure (PAE) causes developmental abnormalities, which may be mediated in part by epigenetic mechanisms. Despite this, few studies have characterised the association of binge PAE with DNA methylation in offspring. Methods: We investigated the association between binge PAE and genome-wide DNA methylation profiles in a sex-specific manner in neonatal buccal and placental samples. Results: We identified no differentially methylated CpGs or differentially methylated regions (DMRs) at false discovery rate <0.05. However, using a sum-of-ranks approach, we identified a DMR in each tissue of female offspring. The DMR identified in buccal samples is located near regions with previously-reported associations to fetal alcohol spectrum disorder (FASD) and binge PAE. Conclusion: Our findings warrant further replication and highlight a potential epigenetic link between binge PAE and FASD.

Syntabulin regulates the trafficking of PICK1-containing vesicles in neurons

PICK1 (protein interacting with C-kinase 1) is a peripheral membrane protein that interacts with diverse membrane proteins. PICK1 has been shown to regulate the clustering and membrane localization of synaptic receptors such as AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptors, metabotropic glutamate receptor 7, and ASICs (acid-sensing ion channels). Moreover, recent evidence suggests that PICK1 can mediate the trafficking of various vesicles out from the Golgi complex in several cell systems, including neurons. However, how PICK1 affects vesicle-trafficking dynamics remains unexplored. Here, we show that PICK1 mediates vesicle trafficking by interacting with syntabulin, a kinesin-binding protein that mediates the trafficking of both synaptic vesicles and mitochondria in axons. Syntabulin recruits PICK1 onto microtubule structures and mediates the trafficking of PICK1-containing vesicles along microtubules. In neurons, syntabulin alters PICK1 expression by recruiting PICK1 into axons and regulates the trafficking dynamics of PICK1-containing vesicles. Furthermore, we show that syntabulin forms a complex with PICK1 and ASICs, regulates ASIC protein expression in neurons, and participates in ASIC-induced acidotoxicity.

Uncovering molecular biomarkers that correlate cognitive decline with the changes of hippocampus' gene expression profiles in Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is characterized by a neurodegenerative progression that alters cognition. On a phenotypical level, cognition is evaluated by means of the MiniMental State Examination (MMSE) and the post-mortem examination of Neurofibrillary Tangle count (NFT) helps to confirm an AD diagnostic. The MMSE evaluates different aspects of cognition including orientation, short-term memory (retention and recall), attention and language. As there is a normal cognitive decline with aging, and death is the final state on which NFT can be counted, the identification of brain gene expression biomarkers from these phenotypical measures has been elusive.

METHODOLOGY/PRINCIPAL FINDINGS

We have reanalysed a microarray dataset contributed in 2004 by Blalock et al. of 31 samples corresponding to hippocampus gene expression from 22 AD subjects of varying degree of severity and 9 controls. Instead of only relying on correlations of gene expression with the associated MMSE and NFT measures, and by using modern bioinformatics methods based on information theory and combinatorial optimization, we uncovered a 1,372-probe gene expression signature that presents a high-consensus with established markers of progression in AD. The signature reveals alterations in calcium, insulin, phosphatidylinositol and wnt-signalling. Among the most correlated gene probes with AD severity we found those linked to synaptic function, neurofilament bundle assembly and neuronal plasticity.

CONCLUSIONS/SIGNIFICANCE

A transcription factors analysis of 1,372-probe signature reveals significant associations with the EGR/KROX family of proteins, MAZ, and E2F1. The gene homologous of EGR1, zif268, Egr-1 or Zenk, together with other members of the EGR family, are consolidating a key role in the neuronal plasticity in the brain. These results indicate a degree of commonality between putative genes involved in AD and prion-induced neurodegenerative processes that warrants further investigation.

Expression of m-Golsyn/Syntabulin gene during mouse brain development

We recently isolated the cDNA for the mouse Golsyn/Syntabulin (m-Golsyn/Syntabulin) gene and mapped it to mouse chromosome 15B3.2 syntenic with human chromosome 8q23, on which a locus responsible for primary open-angle glaucoma had been located. In the present study, we examined the expression of m-Golsyn/Syntabulin protein in various regions of mouse brain and its developmental changes by use of anti-GOLSYN antibody. m-Golsyn/Syntabulin protein was detected in various brain regions at embryonic day 14 and throughout the postnatal stages. Furthermore, as the histogenesis and maturation of brain proceeded, strong expression of the protein became detectable in cells of the choroid plexus, piriform cortex, pyramidal cell layer, and Purkinje cell layer. In situ hybridization analysis of the mouse brain revealed that localization of the m-Golsyn/Syntabulin transcript was very similar to that of m-Golsyn/Syntabulin protein, confirming the high-level expression of the m-Golsyn/Syntabulin gene in the specific brain regions. High-level expression of m-Golsyn/Syntabulin protein was also observed in the ocular tissues including the ciliary body, which is known as a site for the production of aqueous humor. These results may indicate a significant role for this protein in neuronal cells and other types of cells such as those of the choroid plexus and ciliary body.