Molecular characterization of a new scorpion venom lipolysis activating peptide: Evidence for disulfide bridge-mediated functional switch of peptides

Venoms from scorpions contain extremely rich bioactive peptides that often carry diverse functions and are presumably needed to achieve synergistic effects for rapidly immobilizing prey and defending themselves. BotLVP1 is a unique heterodimer protein recently found in the scorpion Buthus occitanus tunetanus venom that is structurally related to scorpion toxins affecting sodium channels (NaScTxs) but exhibits adipocyte lipolysis activity. We have isolated and identified two cDNA clones encoding subunits alpha and beta of a BotLVP1-like peptide (named BmLVP1) from the Chinese scorpion Buthus martensii venom gland and determined the first complete gene structure of this subfamily. These results highlight a genetic link between these lipolysis activating peptides and NaScTxs. Comparison of cDNA and genomic sequences combined with protein structural and functional analysis provides evidence supporting the existence of RNA editing mechanism in scorpion venom glands, which could mediate functional switch of BmLVP1 gene, from adipocyte lipolysis to neurotoxicity, by altering the wrapper disulfide bridge (WDB) pattern of the peptides.

Analysis of oncogenic signaling networks in glioblastoma identifies ASPM as a molecular target

Glioblastoma is the most common primary malignant brain tumor of adults and one of the most lethal of all cancers. Patients with this disease have a median survival of 15 months from the time of diagnosis despite surgery, radiation, and chemotherapy. New treatment approaches are needed. Recent works suggest that glioblastoma patients may benefit from molecularly targeted therapies. Here, we address the compelling need for identification of new molecular targets. Leveraging global gene expression data from two independent sets of clinical tumor samples (n = 55 and n = 65), we identify a gene coexpression module in glioblastoma that is also present in breast cancer and significantly overlaps with the "metasignature" for undifferentiated cancer. Studies in an isogenic model system demonstrate that this module is downstream of the mutant epidermal growth factor receptor, EGFRvIII, and that it can be inhibited by the epidermal growth factor receptor tyrosine kinase inhibitor Erlotinib. We identify ASPM (abnormal spindle-like microcephaly associated) as a key gene within this module and demonstrate its overexpression in glioblastoma relative to normal brain (or body tissues). Finally, we show that ASPM inhibition by siRNA-mediated knockdown inhibits tumor cell proliferation and neural stem cell proliferation, supporting ASPM as a potential molecular target in glioblastoma. Our weighted gene coexpression network analysis provides a blueprint for leveraging genomic data to identify key control networks and molecular targets for glioblastoma, and the principle eluted from our work can be applied to other cancers.

miR-21-mediated tumor growth

MicroRNAs (miRNAs) are approximately 22 nucleotide non-coding RNA molecules that regulate gene expression post-transcriptionally. Although aberrant expression of miRNAs in various human cancers suggests a role for miRNAs in tumorigenesis, it remains largely unclear as to whether knockdown of a specific miRNA affects tumor growth. In this study, we profiled miRNA expression in matched normal breast tissue and breast tumor tissues by TaqMan real-time polymerase chain reaction miRNA array methods. Consistent with previous findings, we found that miR-21 was highly overexpressed in breast tumors compared to the matched normal breast tissues among 157 human miRNAs analysed. To better evaluate the role of miR-21 in tumorigenesis, we transfected breast cancer MCF-7 cells with anti-miR-21 oligonucleotides and found that anti-miR-21 suppressed both cell growth in vitro and tumor growth in the xenograft mouse model. Furthermore, this anti-miR-21-mediated cell growth inhibition was associated with increased apoptosis and decreased cell proliferation, which could be in part owing to downregulation of the antiapoptotic Bcl-2 in anti-miR-21-treated tumor cells. Together, these results suggest that miR-21 functions as an oncogene and modulates tumorigenesis through regulation of genes such as bcl-2 and thus, it may serve as a novel therapeutic target.

Molecular characterization of a possible progenitor sodium channel toxin from the Old World scorpion Mesobuthus martensii

Toxins affecting sodium channels widely exist in the venoms of scorpions throughout the world. These molecules comprise an evolutionarily related peptide family with three shared features including conserved three-dimensional structure and gene organization, and similar function. Based on different pharmacological profiles and binding properties, scorpion sodium channel toxins are divided into alpha- and beta-groups. However, their evolutionary relationship is not yet established. Here, we report a gene isolated from the venom gland of scorpion Mesobuthus martensii which encodes a novel sodium channel toxin-like peptide of 64 amino acids, named Mesotoxin. The Mesotoxin gene is organized into three exons and two introns with the second intron location conserved across the family. This peptide is unusual in that it has only three disulfides and a long cysteine-free tail with loop size and structural characteristics close to beta-toxins. Evolutionary analysis favors its basal position in the origin of scorpion sodium channel toxins as a progenitor. The discovery of Mesotoxin will assist investigations into the key issue regarding the origin and evolution of scorpion toxins.

Effect of femtosecond laser irradiation on structure of UV grade fused silica

A p-polarized femtosecond laser beam was used to irradiate a UV grade fused silica to create microchannels, which are useful for producing optical gratings or micro fluidics devices. The laser irradiated surface was characterized using optical microscope, stylus profiler, SEM, XRD and TEM. A special technique was used to protect the laser irradiated surfaces in preparing cross-sectional TEM samples. The XRD spectra and TEM observation reveal that structure of the fused silica remain amorphous after the femtosecond laser irradiation.

K isomers in 254No: probing single-particle energies and pairing strengths in the heaviest nuclei

We have identified two isomers in 254No, built on two- and four-quasiparticle excitations, with quantum numbers K pi = 8- and (14+), as well as a low-energy 2-quasiparticle Kpi = 3+ state. The occurrence of isomers establishes that K is a good quantum number and therefore that the nucleus has an axial prolate shape. The 2-quasiparticle states probe the energies of the proton levels that govern the stability of superheavy nuclei, test 2-quasiparticle energies from theory, and thereby check their predictions of magic gaps.

No association between the genetic polymorphisms in the RTN4R gene and schizophrenia in the Chinese population

The RTN4R gene is located in the 22q11 region and it encodes a subunit of the receptor complex (RTN4R-p75NTR) which results in neuronal growth inhibitory signals in response to Nogo-66, MAG or OMG signaling. Previous studies have suggested that RTN4R might act as a potential candidate for schizophrenia susceptibility loci. We genotyped four SNPs within the gene and conducted a case-control study and TDT analysis, involving 707 schizophrenic patients, 689 controls and 372 unrelated small nuclear families with schizophrenic offspring in the Chinese population. We examined allele and genotype frequencies and haplotype distributions in both family- and nonfamily-based samples. Our results suggest that there is no significant association between the genetic polymorphisms and schizophrenia in the Han Chinese population.

Decreased survival of C/EBP beta-deficient keratinocytes is due to aberrant regulation of p53 levels and function

Recent studies have identified roles for C/EBPbeta in cellular survival and tumorigenesis, however, the mechanisms through which C/EBPbeta regulates these processes are not fully understood. Previously, we demonstrated that C/EBPbeta(-/-) mice are resistant to carcinogen-induced skin tumorigenesis and in response to topical carcinogen treatment display a 17-fold increase in keratinocyte apoptosis compared to wild-type mice. Here, we have investigated the mechanisms through which C/EBPbeta regulates apoptosis in response to carcinogenic stress. Analysis of carcinogen-treated C/EBPbeta(-/-) mouse skin revealed a striking increase in the number of p53 immunopositive keratinocytes in the epidermis of C/EBPbeta(-/-) mice compared to wild-type mice and this increase was temporally associated with a concomitant anomalous increase in apoptosis. The increased levels of p53 were functional as Mdm2, Bcl-2, C/EBPalpha and p21 were differentially regulated in the epidermis of carcinogen-treated C/EBPbeta(-/-) mice. The increase in p53 protein was not associated with an increase in p53 mRNA levels. To determine whether p53 is required for the increased apoptosis in C/EBPbeta(-/-) mice, C/EBPbeta/p53 compound knockout mice were generated. Carcinogen-treated C/EBPbeta/p53 compound knockout mice did not display increased apoptosis demonstrating p53 is required for the proapoptotic phenotype in C/EBPbeta(-/-) mice. Our results demonstrate that altered keratinocyte survival in C/EBPbeta(-/-) mice results from aberrant regulation of p53 protein and function and indicate C/EBPbeta has a role in the negative regulation of p53 protein levels in response to carcinogen-induced stress.

ZnO nanoparticles embedded in sapphire fabricated by ion implantation and annealing

ZnO nanoparticles were fabricated in sapphire (α-Al(2)O(3) single crystal) by Zn ion implantation (48 keV) at an ion fluence of 1 × 10(17) cm(-2) and subsequent thermal annealing in a flowing oxygen atmosphere. Transmission electron microscopy (TEM) analysis revealed that metallic Zn nanoparticles of 3-10 nm in dimensions formed in the as-implanted sample and that ZnO nanoparticles of 10-12 nm in dimensions formed after annealing at 600 °C. A broad absorption band, peaked at 280 nm, appeared in the as-implanted crystal, due to surface plasma resonance (SPR) absorption of metallic Zn nanoparticles. After annealing at 600 °C, ZnO nanoparticles resulted in an exciton absorption peak at 360 nm. The photoluminescence (PL) of the as-implanted sample was very weak when using a He-Cd 325 nm line as the excitation source. However, two emission peaks appeared in the PL spectrum of ZnO nanopraticles, i.e., one ultraviolet (UV) peak at 370 nm and the other a green peak at 500 nm. The emission at 500 nm is stronger and has potential applications in green/blue light-emitting devices.

Helmet use and bicycle-related trauma in patients presenting to an acute hospital in Singapore

INTRODUCTION

To describe the relationship between bicycle helmet use and injury pattern sustained by patients presenting to an emergency department (ED) in Singapore for bicycle-related trauma.

METHODS

Data was collected from all individuals treated for bicycle-related trauma between September 1, 2004 and May 31, 2005 using a closed-ended questionnaire.

RESULTS

160 bicyclists with mean age of 34.4 years (range 10 to 89 years) were surveyed. Among them, 80 percent were male and 30.6 percent were non-residents. Helmets were worn by 10.6 percent of the patients. Alcohol was clinically detected in 11.3 percent of bicyclists. There was no difference in bicycle helmet use between Singaporeans and non-residents (p-value is 0.275). However, compared to younger bicyclists, bicyclists aged 30 years or older (p-value is less than 0.05), and compared to recreational or sport bicyclists, those who commute by bicycle, tended not to wear helmets (p-value is less than 0.01). Compared to Singaporeans (p-value is less than 0.05), non-residents and bicyclists aged 30 years or older (p-value is 0.011) believed that helmets did not protect against head injury. Comparing the helmeted group with the non-helmeted group, injury patterns by body region were: head injury 5.9 percent versus 40.0 percent (p-value is less than 0.01); facial injury 5.9 percent versus 37.1 percent (p-value is less than 0.05). Not wearing a helmet, being hit by a motor vehicle and age were significantly associated with higher injury severity scores, after adjusting for several potential confounding factors.

CONCLUSION

Bicycle helmet use was low in our sample of injured patients. When worn, protection against injury was demonstrated. A campaign to promote use of bicycle helmets should be targeted at non-residents and older bicyclists. Authorities should consider compulsory helmet laws for bicyclists and expanding anti-drunk driving campaigns to target alcohol-intoxicated bicyclists.

EphB4 receptor tyrosine kinase is expressed in bladder cancer and provides signals for cell survival

We sought to evaluate the biological function of the receptor tyrosine kinase EphB4 in bladder cancer. All of the nine bladder cancer cell lines examined express EphB4 and the receptor could be phosphorylated following stimulation with its cognate ligand, EphrinB2. Out of the 15 fresh bladder cancer specimens examined, 14 expressed EphB4 with a mean sevenfold higher level of expression compared to adjacent normal urothelium. EphB4 expression was regulated by several mechanisms: EPHB4 gene locus was amplified in 27% tumor specimens and 33% cell lines studied; inhibition of EGFR signaling downregulated EphB4 levels; and forced expression of wild-type p53 reduced EphB4 expression. EphB4 knockdown using specific siRNA and antisense oligodeoxynucleotides molecules led to a profound inhibition in cell viability associated with apoptosis via activation of caspase-8 pathway and downregulation of antiapoptotic factor, bcl-xl. Furthermore, EphB4 knockdown significantly inhibited tumor cell migration and invasion. EphB4 knockdown in an in vivo murine tumor xenograft model led to a nearly 80% reduction in tumor volume associated with reduced tumor proliferation, increased apoptosis and reduced tumor microvasculature. EphB4 is thus a potential candidate as a predictor of disease outcome in bladder cancer and as target for novel therapy.

Stabilization of nuclear isovector valence-shell excitations

Excited states in 138Ce have been studied via the 12C(138Ce, 138Ce*) Coulomb excitation reaction at 480 MeV. Relative cross sections have been determined from the gamma-ray yields observed with Gammasphere. The E2 and M1 strength distributions between the lowest six 2+ states up to 2.7 MeV enables us to identify the 2(4)+ state in 138Ce as the dominant fragment of the one-phonon 2(1,ms)+ mixed-symmetry state. Mixing between this level and a nearby isoscalar state is observed and is more than 4 times larger than in the neighboring isotone 136Ba. This is direct evidence that the stability of mixed-symmetry states strongly depends on the underlying subshell structure.

Conditional ablation of C/EBP beta demonstrates its keratinocyte-specific requirement for cell survival and mouse skin tumorigenesis

The CCAAT/enhancer binding protein beta (C/EBP beta) is implicated in the regulation of many different molecular and physiological processes. Mice with a germline deletion of C/EBP beta (C/EBP beta(-/-)) display phenotypes in a multitude of cell types and organ systems, including skin where C/EBP beta(-/-) mice exhibit increased apoptosis in epidermal keratinocytes in response to carcinogen treatment and are completely resistant to carcinogen-induced skin tumorigenesis. To determine the contribution of systemic versus cell autonomous functions of C/EBP beta to specific phenotypes, mice with a conditional 'floxed' C/EBP beta null allele were generated. Epidermal-specific deletion of C/EBP beta was achieved by Cre recombinase expression from a keratin 5 (K5) promoter. Similar to C/EBP beta(-/-) mice, K5-Cre;C/EBP beta(fl/fl) mice were completely refractory to 7,12 dimethylbenz[a]anthracene (DMBA)-induced skin tumorigenesis and these mice displayed increased DMBA-induced apoptosis in epidermal keratinocytes compared to wild-type mice. In contrast, mice lacking the related gene, C/EBP delta, were not resistant to DMBA-induced skin tumorigenesis, indicating a unique role of C/EBP beta in skin tumor development. Our findings demonstrate that C/EBP beta exerts an essential, keratinocyte-intrinsic role in cell survival in response to carcinogen treatment and the elimination of C/EBP beta in keratinocytes is sufficient to confer complete resistance of the skin to chemical carcinogenesis.

Family-based association studies of the TCP1 gene and schizophrenia in the Chinese Han population

A previous case-control study by Yang et al. indicated that the TCP1 gene in 6q25 was associated with schizophrenia in the Han population. To replicate this result, we selected eight SNPs (rs2273828, rs3818298, rs1547094, rs1547093, rs2295898, rs2295899, rs4832, rs15982) spanning the whole gene and performed a family-based study using 325 trios samples. Our transmission disequilibrium test showed neither allele nor haplotype association with schizophrenia, and suggests that the TCP1 locus is not associated with schizophrenia in the Chinese population. Since 6q25 has consistently been found to be a susceptible region for schizophrenia, we suggest that other genes within this region should be the focus of attention.

Photolytic degradation of organic azo dye in aqueous solution using Xe-excimer lamp

The photodegradation of organic azo dye C.I. Food Yellow 4 (FY-4) in aqueous solution was achieved, without the addition of oxidants, by 172 nm vacuum ultraviolet (VUV) radiation emitted from the planar Xe-excimer lamp. The degradation was mainly attributed to the impact of HO radicals produced by water absorbing VUV radiation. The dye decolorization followed pseudo-first order kinetics. The initial quantum yields of FY-4 decolorization in O2-saturated solution and N2-saturated solution were respectively 0.151 +/- 0.003 and 0.103 +/- 0.002. Dissolved oxygen in the solution contributed to the increase of the decolorization rate and chemical oxygen demand (COD) removal rate while KCI added as HO radical scavenger decreased the efficiency of the decolorization and COD removal. It was found from the change of the UV-Vis spectra that the degradation of FY-4 was accompanied by both the cleavage of chromophoric group and the opening of aromatic ring. Major intermediates detected were aromatic compounds, some low molecular weight by-products and several organic acids and inorganic ions.

A novel analytical ELISA-based methodology for pharmacologically active saikosaponins

A competitive enzyme-linked immunosorbent assay (ELISA) for saikosaponins was established using monoclonal antibody (MAb) 3G10. Hybridoma 3G10 prepared by fusing splenocytes immunized with saikosaponin a-BSA (SSa-BSA) conjugate and a hypoxanthine-aminopterin-thymidine (HAT)-sensitive mouse myeloma cell line, P3-X63-Ag8-U1, secreted monoclonal antibodies with wide cross-reactivity to saikosaponins including saikosaponin b(2) (SSb(2)), c (SSc) and d (SSd), which are stereo and/or regio isomers of SSa. The method, at an effective measuring range of 0.6 mug /ml to 2.3 mug/ml of SSa, successfully detected total saikosaponins in Bupleuri radix and Kampo medicines prescribed with Bupleuri radix. Good correlation between ELISA and HPLC analyses of total saikosaponin in a crude extract of Bupleuri radix was obtained after hydrolysis of acyl saikosaponins by treatment with a mild alkaline solution.

Reconstruction of mandibular symphyseal defects by trifocal distraction osteogenesis: an experimental study in Rhesus

Mandibular symphyseal defects caused by tumor surgery, trauma, or congenital misshape can produce maxillofacial deformity and functional handicap. Recently, the technique of distraction osteogenesis has become a valuable reconstructive method for craniofacial bone defects. Four adult rhesus monkeys were used in this study. The anterior mandibulectomy (ranged from canine to canine) was performed, and bilateral transport segments (ranged from first premolar to first molar) were created. Custom-made multiplanar distractors were applied for the reconstruction of the monkeys' artificial mandibular symphyseal defects by trifocal distraction osteogenesis. After a delay period of 7 days, the bilateral transport discs were distracted forward and inward simultaneously. Serial X-ray and three-dimensional CT films were taken within the experimental period. Two monkeys were sacrificed at 8 and 16 weeks, respectively, after the completion of distraction. The distracted calluses and united areas between bilateral transport discs were harvested and processed for histological examination. The mandibular symphyseal defects in all animals were repaired successfully and the anterior mandibular contours were similar to the normal ones. Perfect bone regeneration in the distraction gaps was found, and fibro-bony union between the bilateral transport segments was observed in the midline region at 16 weeks after the end of distraction. The success of distraction osteogenesis for repair of mandibular symphseal defects in monkeys by this distractor may provide an alternative method to reconstruct the anterior part of mandible.

Phylogenetic distribution, functional epitopes and evolution of the CSalphabeta superfamily

A superfamily of proteins often conserves a common structural scaffold but develops diverse biochemical and biological functions during evolution. The understanding of evolutionary mechanisms responsible for this diversity is of fundamental importance not only in structural genomics but also in nature-guided drug design. A superfamily of peptides with a conserved CSalphabeta structural motif provides a considerably intriguing example to approach such an issue. The peptides from this superfamily have wide origins, ranging from plants to animals, and exhibit diverse biological activities, varying from a sweet-tasting protein to antibacterial defensins and animal toxins targeting ion channels. This review describes the phylogenetic distribution and structural classifi cation of this unique scaffold and provides new insights into its functional diversity from the perspective of sequence, structure and evolution.

The transcriptional landscape of the mammalian genome

This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5' and 3' boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development.

Ground state proton radioactivity from 121Pr: when was this exotic nuclear decay mode first discovered?

Ground-state proton radioactivity has been identified from 121Pr. A transition with a proton energy of E(p)=882(10) keV [Q(p)=900(10) keV] and half-life t(1/2)=10(+6)(-3) ms has been observed and is assigned to the decay of a highly prolate deformed 3/2(+) or 3/2(-) Nilsson state. The present result is found to be incompatible with a previously reported observation of ground-state proton radioactivity from 121Pr, which would have represented the discovery of this phenomenon.

Acid Soap and Phase Behavior of Stearic Acid and Triethanolamine Stearate

Crystals of partially neutralized stearic acid with triethanolamine (TEA) were prepared by mixing these two materials above 80 degrees C and then cooling. The crystalline composition and the structure and melting behavior of the resultant products were characterized with small-angle and wide-angle X-ray diffraction, thermal analysis, microscopy, and infrared spectroscopy. It was discovered that an acid-soap complex of 2:1 fixed stoichiometric ratio exists between stearic acid and TEA stearate. A binary phase diagram of stearic acid and TEA soap is built based on the experimental results; this is the first published record of a binary phase diagram for amine-based soap. Its behavior is significantly different from that of binary systems of fatty acid and alkali soap.

In vitro expanded human CD4+CD25+ regulatory T cells suppress effector T cell proliferation

Regulatory T cells (Tregs) have been shown to be critical in the balance between autoimmunity and tolerance and have been implicated in several human autoimmune diseases. However, the small number of Tregs in peripheral blood limits their therapeutic potential. Therefore, we developed a protocol that would allow for the expansion of Tregs while retaining their suppressive activity. We isolated CD4+CD25 hi cells from human peripheral blood and expanded them in vitro in the presence of anti-CD3 and anti-CD28 magnetic Xcyte Dynabeads and high concentrations of exogenous Interleukin (IL)-2. Tregs were effectively expanded up to 200-fold while maintaining surface expression of CD25 and other markers of Tregs: CD62L, HLA-DR, CCR6, and FOXP3. The expanded Tregs suppressed proliferation and cytokine secretion of responder PBMCs in co-cultures stimulated with anti-CD3 or alloantigen. Treg expansion is a critical first step before consideration of Tregs as a therapeutic intervention in patients with autoimmune or graft-versus-host disease.