Diversity of human U2AF splicing factors

U2 snRNP auxiliary factor (U2AF) is an essential heterodimeric splicing factor composed of two subunits, U2AF(65) and U2AF(35). During the past few years, a number of proteins related to both U2AF(65) and U2AF(35) have been discovered. Here, we review the conserved structural features that characterize the U2AF protein families and their evolutionary emergence. We perform a comprehensive database search designed to identify U2AF protein isoforms produced by alternative splicing, and we discuss the potential implications of U2AF protein diversity for splicing regulation.     

Structural and biological characterization of Nattectin, a new C-type lectin from the venomous fish Thalassophryne nattereri

Lectins are glycan-binding receptors that recognize glycan epitopes on foreign pathogens and in the host systems. They can be involved in functions that include innate immunity, development, immune regulation and homeostasis. Several lectins have been purified and characterized from fish species. In this work, using cation-exchange chromatography, a galactose-specific lectin belonging to the family of C-type lectins was isolated from the venom of the Brazilian venomous fish Thalassophryne nattereri. Nattectin is a basic, non-glycosilated, 15 kDa monomeric protein. It exhibits hemagglutination activity that is independent of Ca²⁺. We also demonstrated a lectin activity for Nattectin in the innate immune system, especially in neutrophil mobilization in mice, indicating that marine organisms are source of immunomodulator agents.     

Biomass accumulations and the distribution of nitrogen and phosphorus within three<Emphasis Type="Italic">Quercus acutissima</Emphasis> stands in central Korea

Above- and belowground biomass and nitrogen (N) and phosphorus (P) distribution within threeQuercus acutissima stands were investigated in central Korea. The average age (year) and diameter at breast height (DBH, cm) were 10.8 and 7.9 for Stand 1, 38.2 and 17.1 for Stand 2, and 44.0 and 20.7 for Stand 3, respectively. Fifteen trees were destructively harvested for dimension analysis of component biomass (stem wood, stem bark, foliage, branches, and roots) plus N and P concentrations. Total biomass (t ha^-1) was 88.7 for Stand 1, 154.9 for Stand 2, and 278.1 for Stand 3 while N and P contents in all tree components (kg ha^-1) were 483.3 and 52.2, 697.1 and 55.0, and 1113.9 and 83.7. Nitrogen concentrations were highest in the foliage, followed by the stem bark, branches or roots, and stem wood. In contrast, P concentrations were greatest in the roots, then foliage, branches, stem bark, and stem wood. In general, N and P concentrations in these components significantly decreased with tree age and DBH, while N and P contents significantly increased with age and size. These relationships were stronger for size than for age. Our current data could be utilized to estimate N and P budgets for silvicultural practices, including fertilization, thinning, and harvesting.     

Betulinic and oleanolic acids isolated from Forsythia suspensa Vahl inhibit urease activity of Helicobacter pylori

Sixteen medicinal herbs were selected from a database on traditional herbal materials as well as literature on Korean plant resources. Then ethanol (70%, v/v) extracts of these herbs were tested for inhibition of the urease activity of Helicobacter pylori. The urease activity of H. pylori was strongly (82%) inhibited by extract of Forsythia suspensa Vahl. Active compounds in extract of Forsythia suspensa Vahl were first separated by batch mode solvent extraction, followed by purification by silica gel and octadecyl silica gel column chromatography using solvents of different polarity. According to NMR analysis of the last chromatographic fraction, we identified the presence of betulinic acid and oleanolic acid, which are known to have anti-inflammatory, anti-cancer, and anti-HIV viral activities.     

Design of riboflavin-presenting PAMAM dendrimers as a new nanoplatform for cancer-targeted delivery

This communication describes the synthesis and in vitro biological evaluation of novel generation 5 PAMAM dendrimers conjugated with riboflavin as a targeting ligand. Cell-based experiments demonstrated that a dendrimer conjugated with riboflavin is able to undergo cellular binding and uptake in KB cells, and when the dendrimer is also conjugated with methotrexate, the riboflavin dendrimer conjugate can potently inhibit cell growth.     

Subcellular localisation of VEGF in different pituitary cells. Changes of its expression in oestrogen induced prolactinomas

Summary Vascular endothelial growth factor (VEGF) is an important angiogenic factor in the pituitary gland. The objective of this study was to unveil the VEGF subcellular localisation in different pituitary cell types and to evaluate changes in its expression at different time intervals after oestrogen stimulation. A relevant feature demonstrated was the identification of this cytokine in the nucleus and cytoplasm of lactotrophs, somatotrophs and gonadotrophs, as well as in follicle-stellate cells of male rats. Oestrogen treatment increased the number of VEGF immunopositive cells and its expression detected differentially by western blot in both nucleus and cytoplasm of pituitary cells when compared to the control. At ultrastructural level VEGF appeared associated with nucleolus and euchromatin involving a possible internal autocrine loop. In lactotrophs, the predominant cell of the tumour, VEGF was immunodetected in RER, Golgi complex, and vesicular organelles, supporting further the association with an auto-paracrine effect exerted by VEGF. The nucleus/cytoplasm ratio of VEGF revealed a prevalent accumulation of VEGF in the cytoplasm. The presence of VEGF in the nucleus may probably be associated with a translocation to this cell compartment. This study demonstrated a cytoplasmic and nuclear immunolocalisation of VEGF in normal and tumoural adenohypophyseal cells. In the course of prolactinoma development, the oestrogen stimulated VEGF expression in tumoural cells, promoting a vascular adaptation which contributes to growth and progression of the tumour.     

Lipids and DNA oxidation in Staphylococcus aureus as a consequence of oxidative stress generated by ciprofloxacin

Ciprofloxacin induced an increment of reactive oxygen species in sensitive strains of Staphylococcus aureus leading to oxidative stress detected by chemiluminescence while resistant strains did not suffer such stress. Oxidation of lipids was performed by employing thiobarbituric acid reaction to detect the formation of the amplified intermediate between reactive species oxygen and cytoplasmic macromolecules, namely malondialdehyde (MDA). The sensitive strain presented higher peroxidation of lipids than the resistant strain. The oxidative consequence for DNA was investigated by means of bacteria incubation with ciprofloxacin and posterior extraction of DNA, which was studied by high performance liquid chromatography (HPLC). Sensitive S. aureus ATCC 29213 showed an increase of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) respect controls without antibiotic; there was evident increase of the ratio between 8-oxodG and deoxyguanosine (dG) as a consequence of oxidation of dG to 8-oxodG considered the major DNA marker of oxidative stress. The resistant strain showed low oxidation of DNA and the analysis of 8-oxodG/dG ratio indicated lesser formation of 8-oxodG than S. aureus ATCC 29213.     

A TGF‐β‐induced gene, βig‐h3, is crucial for the apoptotic disappearance of the medial edge epithelium in palate fusion

TGF‐β3, TβR‐I, and TGF‐β‐activated Smad2 has been suggested to be a series of signaling molecules for secondary palate fusion. In this article, we show that a gene induced by TGF‐β, βig‐h3, is coincidentally expressed with TGF‐β3 in medial edge epithelial (MEE) cells undergoing apoptosis during normal palatal fusion. βig‐h3 was also highly expressed in the areas of post‐weaning mammary gland cells and developing phalangeal joints in which TGF‐β3 or BMP‐4‐induced apoptosis occurs, respectively. Blocking of βig‐h3 expression in E12.5 embryos with antisense oligodeoxynucleotides (ODN) resulted in cleft of the secondary palate in 84% of the treated mice that were born. Moreover, the antisense ODN treatment resulted in a failure of apoptosis in the MEE between palatal shelves in physical contact in organ culture. We conclude that βig‐h3 expression in the MEE is stimulated by TGF‐β3, causes cell death, and consequently results in complete fusion of the apposed palatal shelves. J. Cell. Biochem. 107: 818–825, 2009. © 2009 Wiley‐Liss, Inc.     

Effects of UCP2 and UCP3 Variants on the Manifestation of Overweight in Korean Children

To investigate the associations of uncoupling protein (UCP)2 and UCP3 gene variants with overweight and related traits, we genotyped UCP2−866G>A, UCP2Ala55Val, and UCP3−55C>T in 737 Korean children and 732 adults and collected data regarding anthropometric status and blood biochemistry. Information concerning the children's lifestyles and dietary habits was collected. The UCP2−866G>A and UCP3−55C>T gene variants showed significant associations with BMI level, waist circumference, and body weight in the children but not in the adults. Compared with −866GG carriers, the −866GA and AA carriers showed a strong decreasing trend in the risk for overweight (odds ratio (OR), 0.67; 95% confidence interval (CI), 0.45–1.01; P = 0.053). In comparison with UCP3−55CC carriers, children carrying −55CT and TT showed a significant reduction in the risk of overweight (OR, 0.67; 95% CI, 0.46–0.98; P = 0.039). There was also evidence of interactions between the effects of the combined UCP2−UCP3 genotype and obesity‐related metabolic traits. The greatest protective effect against overweight was seen in those with the combined genotype non‐UCP2−866GG and non‐UCP3−55CC, as compared with those carrying both UCP2−866GG and UCP3−55CC (OR, 0.60; 95% CI, 0.38–0.95; P = 0.030). In the subgroup with a low level of physical activity, UCP3−55CC carriers had higher BMI values than UCP3−55T carriers (16.6 ± 2.3 kg/m² vs. 16.1 ± 1.9 kg/m², P = 0.016). Low physical activity may aggravate the susceptibility to overweight in UCP2−866GG and UCP3−55CC carriers.     

Gene expression profiles during differentiation and transdifferentiation of bovine myogenic satellite cells

The molecular mechanisms underlying myogenic satellite cells (MSCs) differentiation into myotube-formed cells (MFCs) and transdifferentiation into adipocyte-like cells (ALCs) are unclear. As a step towards understanding the molecular mechanisms underlying MSC differentiation and transdifferentiation, we attempted to identify the genes differentially expressed during differentiation and transdifferentiation using gene microarray analysis (GMA). Thirty oligonucleotide arrays were used with two technical replicates and nine and six biological replicates for MFCs vs. MSCs and ALCs vs. MSCs, respectively, to contrast expression profile differences. GMA identified 1,224 differentially expressed genes by at least 2-fold during differentiation and transdifferentiation of MSCs. To select the highly expressed genes for future functional study, genes with a 4-fold expression difference were selected for validation by real time RT-PCR and approximately 96.9% of the genes were validated. The up-regulation of marker genes for myogenesis (MYL2, MYH3) and adipogenesis (PPAR??, and FABP4) was observed during the differentiation and transdifferentiation of MSCs into MFCs and ALCs, respectively. KOG analysis revealed that the most of the genes up-regulated during differentiation and transdifferentiation of MSCs were related to signal transduction. Again the exact location of 109 differentially expressed genes by 4-fold were analyzed by chromosome mapping. Among those, co-localization of 29 genes up-regulated during transdifferentiation with QTL for marbling score and intramuscular fat percentage supports the involvement of these genes in cellular transdifferentiation. Interestingly, some genes with unknown function were also identified during the process. Functional studies on these genes may unfold the molecular mechanisms controlling MSC differentiation and transdifferentiation.