Biological significance of miR-126 expression in atrial fibrillation and heart failure

We investigated the biological significance of microRNA-126 (miR-126) expression in patients with atrial fibrillation (AF) and/or heart failure (HF) to examine the possible mechanism of miR-126-dependent AF and development of HF. A total of 103 patients were divided into three groups: AF group (18 men and 17 women, mean age: 65.62±12.72 years), HF group (17 men and 15 women, mean age: 63.95±19.71 years), and HF-AF group (20 men and 16 women, mean age: 66.56±14.37 years). Quantitative real-time PCR was used to measure relative miR-126 expression as calculated by the 2-ΔΔCt method. miR-126 was frequently downregulated in the 3 patient groups compared with controls. This reduction was significantly lower in permanent and persistent AF patients than in those with paroxysmal AF (P<0.05, t-test). Moreover, miR-126 expression was markedly lower in the HF-AF group compared with the AF and HF groups. The 3 patient groups had higher N-terminal prohormone brain natriuretic peptide (NT-proBNP) levels, lower left ventricular ejection fraction (LVEF), larger left atrial diameter, and higher cardiothoracic ratio compared with controls. There were significant differences in NT-proBNP levels and LVEF among the AF, HF, and HF-AF groups. Pearson correlation analysis showed that relative miR-126 expression was positively associated with LVEF, logarithm of NT-proBNP, left atrial diameter, cardiothoracic ratio, and age in HF-AF patients. Multiple linear regression analysis showed that miR-126 expression was positively correlated with LVEF, but negatively correlated with the logarithm of NT-pro BNP and the cardiothoracic ratio (all P<0.05). Serum miR-126 levels could serve as a potential candidate biomarker for evaluating the severity of AF and HF. However, to confirm these results, future studies with a larger and diverse patient population are necessary.

Highly sensitive and selective fluorescent chemosensor for Ni(2+) based on a new poly(arylene ether) with terpyridine substituent groups

A new poly(arylene ether) (PAET) with terpyridine substituent groups has been synthesized which shows a turn-off fluorescent response in the presence of Ni(2+) over other cations and allows discrimination of these cations from each other on the basis of the extent of quenching.

The role of hexokinases from grape berries (Vitis vinifera L.) in regulating the expression of cell wall invertase and sucrose synthase genes

In plants, hexokinase (HXK, EC 2.7.1.1) involved in hexose phosphorylation, plays an important role in sugar sensing and signaling. In this study, we found that at Phase I of grape berry development, lower hexose (glucose or fructose) levels were concomitant with higher HXK activities and protein levels. After the onset of ripening, we demonstrated a drastic reduction in HXK activity and protein levels accompanied by a rising hexose level. Therefore, our results revealed that HXK activity and protein levels had an inverse relationship with the endogenous glucose or fructose levels during grape berry development. A 51 kDa HXK protein band was detected throughout grape berry development. In addition, HXK located in the vacuoles, cytoplasm, nucleus, proplastid, chloroplast, and mitochondrion of the berry flesh cells. During grape berry development, HXK transcriptional level changed slightly, while cell wall invertase (CWINV) and sucrose synthase (SuSy) expression was enhanced after véraison stage. Intriguingly, when sliced grape berries were incubated in different glucose solutions, CWINV and SuSy expression was repressed by glucose, and the intensity of repression depended on glucose concentration and incubation time. After sliced, grape berries were treated with different glucose analogs, CWINV and SuSy expression analyses revealed that phosphorylation of hexoses by hexokinase was an essential component in the glucose-dependent CWINV and SuSy expression. In the meantime, mannoheptulose, a specific inhibitor of hexokinase, blocked the repression induced by glucose on CWINV and SuSy expression. It suggested that HXK played a major role in regulating CWINV and SuSy expression during grape berry development.

Effects of BmKIT 3 R gene transfer on pupal development of Bombyx mori Linnaeus using a Gal4/UAS binary transgenic system

The pupal stage of the silkworm Bombyx mori Linnaeus lasts for approximately two weeks. However, prolongation of pupal duration would reduce the labor required to process and dry fresh cocoons. This study investigated the effects of BmKIT(3)(R) gene (from the Chinese scorpion Buthus martensii Karsch) transfer on the pupal development of B. mori using a Gal4/UAS binary transgenic system. Gal4 driven by a pupa-specific promoter BmWCP4 (from a B. mori wing-cuticle protein gene) or PDP (from a B. mori cocoonase gene), and BmKIT(3)(R) driven by a UAS cis-acting element were used to construct novel piggyBac-derived plasmids containing a neomycin-resistance gene (neo) controlled by the Bombyx mori nucleopolyhedrovirus (BmNPV) ie-1 (immediate-early gene) promoter and a green fluorescent protein gene (gfp) under the control of the B. mori actin 3 (A3) promoter. The vector was transferred into silkworm eggs by sperm-mediated gene transfer. Transgenic silkworms were produced after screening for neo and gfp genes, and gene transfer was verified by polymerase chain reaction and dot-blot hybridization. The larval development of the hybrid progeny of Gal4- and UAS-transgenic silkworms was similar to that of normal silkworms, but some pupae failed to metamorphose into moths, and the development of surviving pupae was arrested as a result of BmKIT(3)(R) expression. Moreover, Gal4 driven by the BmWCP4 promoter delayed pupal development more effectively than that driven by the PDP promoter in the Gal4/UAS binary transgenic system. Pupal durations of hybrid transgenic silkworm progeny with BmWCP4 and PDP promoters were approximately 5, 2, and 4 days longer, respectively, compared to corresponding normal silkworms, BmWCP4/Gal4, and UAS/BmKIT(3)(R) transgenic silkworms, respectively. These results suggest new avenues of research for prolonging the pupal duration of silkworms.

[Analysis of horizontal transfer gene of Bombyx mori NPV]

For research on genetic characters and evolutionary origin of the genome of baculoviruses, a comprehensive homology search and phylogenetic analysis of the complete genomes of Bombyx mori NPV and Bombyx mori were used. Three horizontally transferred genes (inhibitor of apoptosis, chitinase, and UDP-glucosyltransferase) were identified, and there was evidence that all of these genes were derived from the insect host. The results of analysis showed lots of differences between the features of horizontal transferred genes and the ones of whole genomic genes, such as nucleotide composition, codon usagebias and selection pressure. These results reconfirmed that the horizontally transferred genes are exogenous. The analysis of gene function suggested that horizontally transferred genes acquired from an ancestral host insect can increase the efficiency of baculoviruses transmission.

[Analysis of the aminoacyl-tRNA synthetase genes of silkworm (Bombyx mori)]

For further research on number, type, composition and origin of Bombyx mori aminoacyl-tRNA synthetase (BmaaRS) genes, in silico cloning was performed with Bombyx mori genomic and EST databases. There might be two different sets of aaRS nuclear gene in Bombxy nori genome, which encode mitochondrial BmaaRS and cytoplasmic BmaaRS, respectively. Among BmaaRS genes, there were 2 genes encoding mitochondrial BmSerRS, but no genes encoding cytoplasmic BmHisRS and mitochondrial BmGlnRS, BmLysRS, BmGlyRS, and BmThrRS. The functions of these absent genes could be directly replaced by other proteins with similar functions, or might undergo their distinct BmaaRS functions based on the alternative splice of one certain BmaaRS mRNA. Evidence of EST indicated that BmaaRS performed different alternative splicing patterns. The homology comparison and advanced structural analysis of BmaaRS demonstrated the existence of extended domains of BmaaRS. This is because some different BmaaRSs contained similar domain. Moreover, BmaaRSs with similar functions possessed the similar tertiary structure. Phylogenetic analysis revealed that BmaaRS encoded by two various sources of BmaaRS genes. Mitochondrial and cytoplasmic BmaaRS had different origin.

Inactivation Analysis of HcNPV Cysteine Protease Gene and Chitinase Gene

The fragment of Hyphantria cunea nuclear polyhedrosis virus (HcNPV), which contains cysteine protease gene(CP) and chitinase gene (ChiA),was inserted into plasmid PCRII to construct transfer vector pHcCVdel. Recombinant transfer vector pHcCvpolh was constructed by inserting the fragment of HcNPV polyhedrin gene (polh) into the EcoRI site of the pHcCVdel. By contransfection of the pHcCvpolh and HcNPV-PTTH(+) DNA, which contained Bombyx mori prothoracicotropic hormone gene (PTTH) into SPIM cells, the region from +76 downstream of ChiA gene initiation codon to +20 downstream of CP gene initiation codon was substituted by the polh gene, and the recombinant virus HcNPVpolh(+)CP(-)ChiA(-)PTTH(+) was produced. The recombinant virus, in which CP gene and ChiA gene were inactive, could express PTTH gene and form polyhedra. SPIM cells infected with the recombinant virus revealed that CP and ChiA gene were not essential for viral replication and had no significant effect on polyhedron formation, but the infected cells survived 2 days more than those infected with HcNPV and HcNPVPTTH(+). Therefore, the expression time of foreign gene may be prolonged when CP gene and ChiA gene were inactivated.

Nucleotide Sequence Analysis of the HcNPV Cysteine Protease Gene

The cysteine protease (CP) gene of Hyphantria cunea nuclear polyhedrosis virus (HcNPV) has been located at the Hind III--3.5 kb fragment. The nucleotide sequence has been determined. The results indicated that its open reading frame of 975 nt encoded the protein of 324 amino acids. The baculovirus late gene promoter TAAG motif was identified at -24 nt upstream from the start codon ATG; The typical poly (A) signal sequence AATAAA was detected at 33 nt downstream from the stop codon TAA. The HcNPV CP exhibited 81%, 76% and 76% homology at the nucleotide level, and 85%, 78%, 76% homology at the amino acid level to that of CfNPV (Choristoneura fumiferana nuclear polyhedrosis virus), AcNPV (Autographa californica nuclear polyhedrosis virus) and BmNPV (Bombyx mori nuclear polyhedrosis virus), respectively. HcNPV CP was a memeber of the papain superfamily and showed high homology to other cysteine protease, particularly, to those from Trypanosoma brucei and Dictyostelium discoideumwith 31.8%, 34.5% identity at the amino acid level, respectively. Of 36 residues conserved among cathepsins B, H, L and S and papain, 32 were identical in HcNPV CP. The ERFNIN interspersed amino acid motif was found within the propeptide region of the HcNPV CP. The Gly-Cys-Asn-Gly-Gly motif conserved among all cysteine protease was also detected in HcNPV CP.

Accumulation of phosphocreatine and creatine in the cells and fluid of mouse seminal vesicles is regulated by testosterone

We have recently established that phosphocreatine (PCr), a high-energy phosphate compound known to serve as an intracellular energy reserve, accumulates in the seminal vesicular fluid (SVF) of the mouse and the rat. To investigate whether the accumulation of PCr in the extracellular fluid of the seminal vesicles of mice is androgen-dependent, young adult mice (Swiss Webster, 6-7 wk old) were orchidectomized. Involution of the seminal vesicles following orchidectomy resulted in the total absence of SVF. Administration of testosterone propionate (TP) 2 wk later at a daily dose of 5 micrograms/g b.w. caused a rapid increase in the weights of seminal vesicle tissue (SVT) and SVF and also increased the concentration of PCr in SVF. The concentration of PCr in SVF increased rapidly from 3.0 mumol/g on Day 2 to a peak value of 11.1 +/- 0.5 mumol/g on Day 6. The increase in PCr concentration in SVF coincided with the enhanced rate of secretion of specific proteins by androgen-responsive epithelial cells. The creatine (Cr) concentration in SVF also increased from 12.6 mumol/g on Day 2 to 41.1 +/- 4.6 mumol/g on Day 8. The concentrations of PCr in SVF of TP-treated mice were about twice those in the age-matched intact controls. The concentrations of PCr and of Cr in SVT also increased from 1.1 +/- 0.5 mumol/g and 1.7 +/- 0.8 mumol/g, respectively, on Day 0 to the steady-state levels of 5.3 +/- 0.7 mumol/g and 14.8 +/- 2.7 mumol/g by Day 8. These results demonstrate that the accumulation of PCr in the fluid of mouse seminal vesicle is regulated by androgen.