Characterization of ORF29 of Bombyx mori nucleopolyhedrovirus

ORF 29 of Bombyx mori nucleopolyhedrovirus (BmNPV ORF29), a conserved gene among all the lepidopteran baculoviruses, was subjected to analysis of sequence and transcription/translation in the insect BmN cells in vitro. His-tagged BmNPV ORF29 fusion protein was expressed in Escherichia coli, purified and used for the production of an antiserum. All the homologs of BmNPV ORF29 in baculoviruses contain a Nudix motif with slight modifications in the N-terminal part. A 654 nts-long transcript of BmNPV ORF29 in BmN cells was detected at 3-48 hrs p.i. indicating the early nature of the gene. In the virus-infected cells, the BmNPV ORF29 protein of 26 K was present in both the cytoplasm and nucleus. In the virions, the protein was present in Budded virus (BV), but not in Occlusion-derived virus (ODV). These results suggest that BmNPV ORF29 is a functional ORF of BmNPV, which encodes a 26 K protein expressed in the early stage of infection cycle.

Feeding-based RNA interference of a trehalose phosphate synthase gene in the brown planthopper, Nilaparvata lugens

The brown planthopper, Nilaparvata lugens, is the most devastating rice insect pest to have given rise to an outbreak in recent years. RNA interference (RNAi) is a technological breakthrough that has been developed as a powerful tool for studying gene function and for the highly targeted control of insect pests. Here, we examined the effects of using a feeding-based RNAi technique to target the gene trehalose phosphate synthase (TPS) in N. lugens. The full-length cDNA of N. lugens TPS (NlTPS) is 3235 bp and has an open reading frame of 2424 bp, encoding a protein of 807 amino acids. NlTPS was expressed in the fat body, midgut and ovary. Quantitative real-time PCR (qRT-PCR) analysis revealed that NlTPS mRNA is expressed continuously with little change during the life of the insect. Efficient silencing of the TPS gene through double-stranded RNA (dsRNA) feeding led to rapid and significant reduction levels of TPS mRNA and enzymatic activity. Additionally, the development of N. lugens larvae that had been fed with the dsRNA was disturbed, resulting in lethality, and the cumulative survival rates dropped to 75.56, 64.44, 55.56 and 40.00% after continuous ingestion of 0.5 µg/µl dsRNA for 2, 4, 7 and 10 days, respectively. These values were significantly lower than those of the insects in the control group, suggesting that NlTPS dsRNA may be useful as a means of insect pest control.

Proteomic analysis of 3T3-L1 preadipocytes having a higher cell proliferation rate after treatment with low-molecular-weight silk fibroin peptides

OBJECTIVES

Previous studies have reported that fibroin peptides can be used in a new strategy for development of anti-diabetic peptide drugs. In this study, we separated silk fibroin hydrolysates (SFH) containing silk fibroin peptides into four components according to their molecular weight and tested the effects of these together with three synthetic silk fibroin hexapeptides GAGAGS, GAGAGY, GAGAGA on cell proliferation of 3T3-L1 preadipocytes. The aim of this study was to investigate protein expression profiles of 3T3-L1 preadipocytes and those treated with SFH component Fraction I and the synthetic silk fibroin hexapeptide GAGAGS to be able to elucidate difference in protein expression between the 3T3-L1 preadipocytes and those treated with fibroin peptides Fraction I and GAGAGS.

MATERIALS AND METHODS

SFH was separated by dialysis. MTT assays were performed to test effects of SFH components and synthetic silk fibroin hexapeptides on 3T3-L1 preadipocyte proliferation. We generated proteome maps using two-dimensional gel electrophoresis and analysed them by peptide mass fingerprinting.

RESULTS

GAGAGS and peptide mixtures, Fraction I and Fraction II, had significant effect in promoting 3T3-L1 preadipocyte proliferation. In the proteomic analysis, 73 protein spots were successfully identified, including 15 which were differentially expressed.

CONCLUSIONS

Our results show that some silk fibroin peptides of low molecular weight SFH and hexapeptide GAGAGS affected 3T3-L1 preadipocyte proliferation.

The synergistic effect of recombinant human endostatin (YH-16) combined with oxaliplatin on human colorectal carcinoma

This study was designed to investigate the effect of recombinant human endostatin (YH-16) combined with oxaliplatin (L-OHP) on the growth of orthotopically-implanted human colorectal carcinoma in nude mice. Tumour volumes and weights were measured after therapy. Tumour cell morphology was observed by light and electron microscopy. Apoptosis was detected using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelling (TUNEL) assay, and vascular endothelial growth factor (VEGF) expression and microvessel density (MVD) were determined by immunohistochemical staining. Tumour volumes in all treatment groups were significantly reduced compared with controls. YH-16 and L-OHP either alone or in combination caused tumour cell apoptosis, except in the YH-16 low-dose group. MVD was strongly inhibited in the treatment groups compared with the controls, although only YH-16 combined with L-OHP or L-OHP alone decreased VEGF expression. No obvious change in side-effects occurred. In conclusion, YH-16 combined with L-OHP inhibited growth and induced apoptosis in orthotopically-transplanted human colorectal carcinoma in nude mice without increasing side-effects.

The Presence of Hepatitis B Surface Antigen in the Ova of Pregnant Women and Its Relationship with Intra-Uterine Infection by Hepatitis B Virus

Vertical transmission of hepatitis B virus (HBV) has been proposed to play an important role in mother-to-child transmission, although the extent to which vertical transmission via oocytes contributes to neonatal HBV infection remains unknown. Ovarian biopsies were collected during caesarean sections in 68 clinically asymptomatic pregnant women who were carriers of HBV. The presence of hepatitis B surface antigen (HBsAg) in the ova of pregnant women was determined by immunohistochemistry. Serum markers of HBV infection in pregnant women and their neonates were analysed. It was found that, of 68 women, the ova were positive for HBsAg in only one woman and her neonate was negative for any serum HBV markers 3 days after birth. Of 68 neonates, one was positive for serum HBV markers 3 days after birth and his mother's ova were negative for HBsAg. These findings indicate that vertical transmission via oocytes may not be the major route of HBV intra-uterine infection.

A genome-wide survey on basic helix-loop-helix transcription factors in rat and mouse

The basic helix-loop-helix (bHLH) proteins play essential roles in a wide range of developmental processes in higher organisms. bHLH family members have been identified in over 20 organisms, including nematode, fruit fly, and human. Our study identified 114 rat and 14 additional mouse bHLH members in rat and mouse genomes, respectively. Phylogenetic analyses revealed that both rat and mouse had 49, 26, 15, 4, 12, and 4 bHLH members in groups A, B, C, D, E, and F, respectively. Only the rat Mxi1 gene has two copies in the genome. All other rat bHLH genes and all mouse bHLH genes are single-copy genes. The chromosomal distribution pattern of mouse, rat, and human bHLH genes suggests the emergence of some bHLH genes through gene duplication, which probably happened at least before the divergence of vertebrates from invertebrates. The present study provides useful information for future studies using rat as a model animal for mammalian development.