Resveratrol protects SH-SY5Y neuroblastoma cells from apoptosis induced by dopamine

Dopamine (DA) is an oxidant that may contribute to the degeneration of dopaminergic neurons. The present study demonstrates that DA-induced cytotoxicity in human-derived neurotypic cells, SH-SY5Y, is prevented by resveratrol, one of the major antioxidative constituents found in the skin of grapes. SH-SY5Y cells, a neuroblastoma cell line, treated with DA at 300 and 500 micrometer for 24 h underwent apoptotic death as determined by characteristic morphological features, including nuclear condensation, and loss of mitochondrial membrane potential (MMP). Flow cytometric analysis using Annexin V showed that DA can induce significant and severe apoptosis. Exposure to resveratrol (5 micrometer) for 1 h prior to the DA treatment attenuated DA-induced cytotoxicity, and rescued the loss of MMP. To investigate the apoptotic signaling pathways relevant to the restoration of DA-induced apoptosis by resveratrol, we carried out quantitative analysis of Bcl-2, caspase-3, and cleaved poly ADP-ribose polymerase (PARP) by immunoblot analysis. Resveratrol pretreatment led to a decrease in cleavage of PARP, an increase in the Bcl-2 protein, and activation of caspase-3. These results suggest that DA may be a potential oxidant of neuronal cells at biologically relevant concentrations. Resveratrol may protect SH-SY5Y cells against this cytotoxicity, reducing intracellular oxidative stress through canonical signal pathways of apoptosis and may be of biological importance in the prevention of a dopaminergic neurodegenerative disorder such as Parkinson disease.

Characterization of E. coli-induced Genes in Bombyx mori Fatbody using Expressed Sequence Tags Analysis

To accelerate the molecular analysis of specifically induced antibacterial peptide against pathogen (E. coli), cDNA library prepared from the larvae fatbody of Bombyx mori was examined by the expressed sequence tag (EST) analysis. In a total of 722 clones, 653 clones were unique genes. Of 653 unique genes, 43.2% (282/653 ESTs) was identified as characterized genes, 38.1% (249/653 ESTs) as uncharacterized genes, and 18.7% (122/653 ESTs) as novel ESTs. According to the functional categorization of the characterized genes, 36.2% (102/282 ESTs) was antibacterial proteins. The highest expressed peptides, 78.4% of all the expressed antibacterial proteins (80/102 ESTs), belonged to the cecropin family. The antibacterial effect of selected clones representing novel ESTs based on a phylogenetic analysis was examined against various bacterial strains. None of the clones showed significant inhibitory effect to the bacteria tested. These results suggested that most of the novel molecules induced by E. coli may not act as immune-induced antibacterial peptides in the fatbody.

Genomic organization and expression of parkin in Drosophila melanogaster

We report here the isolation, characterization on genomic structure and expression of the D. melanogaster homolog of human parkin. The 2,122 bp parkin gene sequence contains six exons that form a 1,449 bp transcript encoding a protein of 482 amino acids. 151 bp of 5' and 112 bp of 3' untranslated regions were identified by a combination of 5'-RACE/primer extension and 3'-RACE, respectively. The 5' UTR contains three transcription initiation sites. Neither a classical TATA nor a CAAT box was found in the putative promoter sequence. However, binding sites for AhR-Arnt, AP4, NF1 and GATA transcription factors were identified. Transient transfection analysis of the 5' UTR confirmed its promoter activity in HEK 293 cells and SH-SY5Y neuronal cells using a dual luciferase reporting system. The amino acid sequence of D. melanogaster Parkin exhibits 42%, 43% and 43% identity to that of human, mouse and rat, respectively, representing a 54 kDa protein band via western blot analysis. It shows a high degree of conservation in the Ubiquitin-like domain at the N-terminus (34%), the In-Between RING finger domains (IBR, 65-69%), and the RING finger domains at the C-terminus (56-57%). The expression pattern of D. melanogaster parkin varies during the developmental stages, with the highest expression in the adult stage as measured by competitive RT-PCR. From immunostainings of the embryo, D. melanogaster parkin was expressed slightly higher in the central nervous system (brain and nerve cord) during the late embryonic stage.

The Optimal Conditions of Chromosomal Analysis in Peripheral Blood / 대한산부인과학회잡지

OBJECTIVE: To find out the optimal conditions of human chromosomal analysis protocol in peripheral blood sample. METHODS: The experiments were made with the variations of phytohaemagglutinin, colcemid, ethidium bromide concentration and the variations of hypotonic solution exposure time. RESULTS: In the experiment on the optimal phytohaemagglutinin concentration, the highest mitotic index in the overall collected cells was obtained in phytohaemagglutinin concentration 15microL/ml. In the experiment on the concentration of mitotic arrestant colcemid, the proper chromosomal state that is meta phase stage and doesn't have many chromosomal crossings or tangles was obtained in colcemid concentration 0.05microg/ml. In the experiment on the optimal exposure time of hypotonic solution(0.075M KCl) treatment, the most suitable intervals between chromosomes were subtained in 20 minutes. In the experiment on the optimal concentration of ethidium bromide to obtain minute chromosomal bands, the best result was when ethidium bromide concentration 5microg/ml or 7.5microg/ml was addition to colcemid concentration 0.02microg/ml. CONCLUSION: The combination of phytohaemagglutinin 15microL/ml, colcemid 0.05microg/ml, hypotonic solution exposure time for 20 minutes is important to the collection of appropriate chromosome state in human chromosomal analysis using peripheral blood. In the case that needs to obtain minute bands, the elongated chromosomes are obtained when ethidium bromide 5microg/ml or 7.5microg/ml in addition to colcemid concentration 0.02microg/ml with the same conditions of phytohaemagglutinin and hypotonic solution.