Mammalian spermatozoa become fully motile and fertile during transit through the luminal fluid of the epididymis. At least 200 proteins are present in the epididymal lumen, but the potential roles of these luminal proteins in male fertility are unknown. Investigation of the function of these proteins will elucidate the mechanism of sperm maturation, and also provide new drug targets for male contraception. We cloned RNase9 from a human epididymis cDNA library for characterization and analysis of its functions.
It was predicted that human RNase9 gene was located on chromosome 14q11.2 and encoded a 205 amino acids protein with a signal peptide of 26 amino acids at the N-terminus. The protein had eight conserved cysteine residues characteristic of the RNase A family members and several potential post-translational modification sites.
At the transcriptional level, RNase9 was expressed in a wide variety of tissues, and the expression was higher in men than in boys. RNase9 was localized to the post-equatorial region of the sperms' head. Immunofluorescence staining showed that RNase9 protein was present mostly in the epithelium of the epididymal tubule. Recombinant RNase9 had no ribonuclease activity. In addition, RNase9 had no detectable effect on sperm motility and fertilization as demonstrated by blocking spermatozoa with anti-RNase9 polyclonal serum.
RNase9 is expressed in a wide variety of tissues. It is located on the post-equatorial region of the sperm head and the epithelium of epididymal tubule. Although RNase9 belongs to the RNase A family, it has no ribonuclease activity.
Guanosine at position 26 in eukaryotic tRNAs is usually modified to N2 , N2 -dimethylguanosine (m22G26). In Saccharomyces cerevisiae , this reaction is catalysed by the TRM1 encoded tRNA (m22G26)dimethyltransferase. As a prerequisite for future studies, the yeast TRM1 gene was expressed in Escherichia coli and the His-tagged Trm1 protein (rTrm1p) was extensively purified. rTrm1p catalysed both the mono- and dimethylation of G26 in vivo in Escherichia coli tRNA and in vitro in yeast trm1 mutant tRNA. The TRM1 gene from two independent wild-type yeast strains differed at 14 base positions causing two amino acid exchanges . Exchange of the original Ser467 for Leu caused a complete loss of enzyme activity in vitro against trm1 yeast tRNA. Comparatively short N- or C-terminal deletions from the 570 amino acid long Trm1 polypeptide decreased or eliminated the enzyme activity, as did some point mutations within these regions. This indicated that the protein is not a two domain peptide with the enzyme activity localised to one of the domains, but rather that both ends of the polypeptide seem to interact to influence the conformation of those parts that make up the RNA-binding site and/or the active site of the enzyme.
In the title compound, C17H14O6, the dihedral angle between the two anhydride rings is 76.01 (8)°while the dihedral angles between the benzene and anhydride rings are 42.60 (7) and 68.94 (7)°. The cyclohexene ring of the tetrahydronaphthalene unit exhibits an envelope conformation.
China's seas cover nearly 5 million square kilometers extending from the tropical to the temperate climate zones and bordering on 32,000 km of coastline, including islands. Comprehensive systematic study of the marine biodiversity within this region began in the early 1950s with the establishment of the Qingdao Marine Biological Laboratory of the Chinese Academy of Sciences. Since that time scientists have carried out intensive multidisciplinary research on marine life in the China seas and have recorded 22,629 species belonging to 46 phyla. The marine flora and fauna of the China seas are characterized by high biodiversity, including tropical and subtropical elements of the Indo-West Pacific warm-water fauna in the South and East China seas, and temperate elements of North Pacific temperate fauna mainly in the Yellow Sea. The southern South China Sea fauna is characterized by typical tropical elements paralleled with the Philippine-New Guinea-Indonesia Coral triangle typical tropical faunal center.
This paper summarizes advances in studies of marine biodiversity in China's seas and discusses current research mainly on characteristics and changes in marine biodiversity, including the monitoring, assessment, and conservation of endangered species and particularly the strengthening of effective management. Studies of (1) a tidal flat in a semi-enclosed embayment, (2) the impact of global climate change on a cold-water ecosystem, (3) coral reefs of Hainan Island and Xisha-Nansha atolls, (4) mangrove forests of the South China Sea, (5) a threatened seagrass field, and (6) an example of stock enhancement practices of the Chinese shrimp fishery are briefly introduced. Besides the overexploitation of living resources (more than 12.4 million tons yielded in 2007), the major threat to the biodiversity of the China seas is environmental deterioration (pollution, coastal construction), particularly in the brackish waters of estuarine environments, which are characterized by high productivity and represent spawning and nursery areas for several economically important species. In the long term, climate change is also a major threat. Finally, challenges in marine biodiversity studies are briefly discussed along with suggestions to strengthen the field. Since 2004, China has participated in the Census of Marine Life, through which advances in the study of zooplankton and zoobenthos biodiversity were finally summarized.
Prior studies have suggested that BRCA-related epithelial ovarian cancer (EOC) conveys improved survival compared to sporadic EOC, but few studies have studied differences between BRCA genotypes. We compared characteristics and outcome by genotype in BRCA-associated EOC.
BRCA-associated EOC patients, between 01/30/1981 and 12/30/2008, were retrospectively identified through IRB-approved registry studies. Clinical characteristics, including event-free (EFS) and overall survival (OS), for BRCA1 vs. BRCA2 were examined.
197 cases were identified (148 BRCA1; 49 BRCA2); median follow-up was 63 months. BRCA2 patients were older (55.4 vs. 51.1 years; p<0.01) and had fewer poorly-differentiated tumors (67% vs. 82%; p<0.05). No difference in EFS was observed. OS at 5-years was 75% in BRCA2 vs. 61% in BRCA1 patients; this was not statistically significant. A non-significant trend towards improved OS was observed in BRCA2 patients with advanced-stage disease (HR = 0.59, 95% CI 0.32–1.08).
Age and grade differed significantly between BRCA1 and BRCA2 carriers in our study population. While no overall differences in EFS or OS were observed, there was a trend towards improved OS in BRCA2 carriers with advanced-stage disease. This may reflect important differences between BRCA genotypes and should be validated in larger studies.
BRCA1; BRCA2; Ovarian carcinoma; Genetics; Cancer
Inorganic arsenic (iAs) is an environmental toxicant and human carcinogen. The enzymatic methylation of iAs that is catalyzed by arsenic (+3 oxidation state)-methyltransferase (AS3MT) generates reactive methylated intermediates that contribute to the toxic and carcinogenic effects of iAs. We have shown that clonal human urothelial cells (UROtsa/F35) that express rat AS3MT and methylate iAs are more susceptible to acute toxicity of arsenite (iAsIII) than parental UROtsa cells that do not express AS3MT and do not methylate iAs. The current work examines transcriptional changes associated with AS3MT expression and identifies specific categories of genes expressed in UROtsa and UROtsa/F35 cells in response to a 24-h exposure to 1 or 50 μM iAsIII. Here, the expression of 21,073 genes was assessed using Agilent Human 1A(V2) arrays. Venn analysis showed marked concentration-dependent differences between gene expression patterns in UROtsa and UROTsa/F35 cells exposed to iAsIII. Among 134 genes altered by exposure to subtoxic 1 μM iAsIII, only 14 were shared by both cell lines. Exposure to cytotoxic 50 μM iAsIII uniquely altered 1389 genes in UROtsa/F35 and 649 genes in UROtsa cells; 5033 altered genes were associated with the chemical alone. In UROtsa, but not UROtsa/F35 cells exposure to 1 μM iAsIII altered expression of genes associated with cell adhesion. In contrast, expression of genes involved in cell cycle regulation was significantly altered in UROtsa/F35 cells at this exposure level. At 50 μM iAsIII, pathways regulating cell cycle, cell death, transcription, and metabolism were affected in both cell lines. However, only Urotsa/F35 cells showed numerous G-protein and kinase pathway alterations as well as alterations in pathways involved in cell growth and differentiation. These data link the AS3MT-catalyzed methylation of iAs to specific genomic responses in human cells exposed to iAsIII. Further analysis of these responses will help to characterize the role of AS3MT-catalyzed methylation in modulation of iAsIII toxicity.
arsenite; AS3MT; human urothelial cells; transcriptional profiles
To demonstrate the feasibility of simultaneous dual fundamental grayscale and subharmonic imaging on a modified commercial scanner.
The ability to generate signals at half the insonation frequency is exclusive to ultrasound contrast agents (UCA). Thus, subharmonic imaging (SHI; transmitting at f0 and receiving at f0/2) provides improved visualization of UCA within the vasculature via suppression of the surrounding tissue echoes. While this capability has proven useful in a variety of clinical applications, the SHI suppression of surrounding tissue landmarks (which are needed for sonographic navigation) also limits it use as a primary imaging modality. In this paper we present results using a commercial ultrasound scanner modified to allow imaging in both grayscale (f0 = 4.0 MHz) and SHI (f0 = 2.5 MHz, f0/2 = 1.25 MHz) modes in real time.
A Logiq 9 ultrasound scanner (GE Healthcare, Milwaukee, WI) with a 4C curvilinear probe was modified to provide this capability. Four commercially available UCA (Definity, Lantheus Medical Imaging, North Billerica, MA; Optison, GE Healthcare, Princeton, NJ; SonoVue Bracco Imaging, Milan, Italy; and Sonazoid GE Healthcare, Oslo, Norway) were all investigated in vitro over an acoustic output range of 3.34 MPa. In vivo the subharmonic response of Sonazoid (GE Healthcare, Oslo, Norway) was investigated in the portal veins of 4 canines (open abdominal cavity) and 4 patients with suspected portal hypertension.
In vitro, the four UCA showed an average maximum subharmonic amplitude of 44.1 ± 5.4 dB above the noise floor with a maximum subharmonic amplitude of 48.6 ± 1.6 dB provided by Sonazoid. The average in vivo maximum signal above the noise floor from Sonazoid was 20.8 ± 2.3 dB in canines and 33.9 ± 5.2 dB in humans. Subharmonic amplitude as a function of acoustic output in both groups matched the S-curve behavior if the agent observed in vitro. The dual grayscale imaging provided easier sonographic navigation while the degree of tissue suppression in SHI mode varied greatly on a case by case basis.
These results demonstrate the feasibility of dual grayscale and SHI on a modified commercial scanner. The ability to simultaneously visualize both imaging modes in real time should improve the applicability of SHI as a future primary clinical imaging modality.
Subharmonic imaging; ultrasound contrast agents; contrast-enhanced ultrasound
p53 has a crucial role in governing cellular mechanisms in response to a broad range of genotoxic stresses. During DNA damage, p53 can either promote cell survival by activating senescence or cell-cycle arrest and DNA repair to maintain genomic integrity for cell survival or direct cells to undergo apoptosis to eliminate extensively damaged cells. The ability of p53 to execute these two opposing cell fates depends on distinct signaling pathways downstream of p53. In this study, we showed that under DNA damage conditions induced by chemotherapeutic drugs, gamma irradiation and hydrogen peroxide, p53 upregulates a novel protein, proline-rich acidic protein 1 (PRAP1). We identified functional p53-response elements within intron 1 of PRAP1 gene and showed that these regions interact directly with p53 using ChIP assays, indicating that PRAP1 is a novel p53 target gene. The induction of PRAP1 expression by p53 may promote resistance of cancer cells to chemotherapeutic drugs such as 5-fluorouracil (5-FU), as knockdown of PRAP1 increases apoptosis in cancer cells after 5-FU treatment. PRAP1 appears to protect cells from apoptosis by inducing cell-cycle arrest, suggesting that the induction of PRAP1 expression by p53 in response to DNA-damaging agents contributes to cancer cell survival. Our findings provide a greater insight into the mechanisms underlying the pro-survival role of p53 in response to cytotoxic treatments.
PRAP1; p53; DNA damage; cell-cycle arrest
Doublecortin (DCX) is one of two major genetic loci underlying human lissencephaly, a neurodevelopmental disorder with defects in neuronal migration and axon outgrowth. DCX is a microtubule-binding protein, and much work has focused on its microtubule-associated functions. DCX has other reported binding partners, including the cell adhesion molecule neurofascin, but the functional significance of the DCX-neurofascin interaction is not understood. Neurofascin localizes strongly to the axon initial segment in mature neurons where it plays a role in assembling and maintaining other axon initial segment components. During development, neurofascin likely plays additional roles in axon guidance and in GABAergic synaptogenesis. We show here that DCX can modulate the surface distribution of neurofascin in developing cultured rat neurons, and thereby the relative extent of accumulation between the axon initial segment, and soma and dendrites. Mechanistically, DCX acts via increasing endocytosis of neurofascin from soma and dendrites. Surprisingly, DCX increases neurofascin endocytosis apparently independently of its microtubule-binding activity. We additionally show that the patient allele DCXG253D still binds microtubules, but is deficient in promoting NF endocytosis. We propose that DCX acts as an endocytic adaptor for neurofascin to fine-tune its surface distribution during neuronal development.
DCX; neurofascin; axon initial segment; endocytosis; dendrite; trafficking
Matrix metalloproteinase-2 (MMP-2) degrades type IV collagen and enables endothelial cell (EC) migration during angiogenesis and wound healing. PEX2 is a byproduct of activated MMP-2 autocatalysis and competitively inhibits newly activated MMP-2 from EC surface binding and migration. We hypothesize that PEX2 is elevated during limb ischemia, contributing to poor wound healing by interfering with angiogenesis. We aim to identify elevated PEX2 in ischemic murine hindlimb muscle and demonstrate poor healing with decreased capillary density.
Western blot was used to identify PEX2 in hindlimbs of FVB/NJ mice with surgically induced ischemia. The PEX2 effect on healing was evaluated by calculating area of exposed muscle after wounding the dorsum of mice and performing daily injections with recombinant PEX2 (hrPEX2). Additionally, wounds were injected with lentivirus expressing PEX2 (PEX2-LV), harvested on post operative day 7 (POD 7), fixed and sectioned for staining with hematoxylin and eosin (H&E). Epithelial gap was assessed with light microscopy. Capillary density was evaluated after wounding Tie2-GFP+ transgenic FVB mice (ECs labeled green) and viral transduction with PEX2-LV. Wounds were harvested on POD 7, frozen in liquid nitrogen, sectioned and stained with Hoechst. Vessel density was assessed via fluorescence microscopy as average number of capillaries per ten high powered fields (HPF). Paired Student’s t-test was used to assess differences between the groups.
PEX2 was elevated 5.5-fold (±2.0, P= .005) on POD 2 and 2.9-fold (±0.69, P= .004) on POD 4 in gastrocnemius muscles of ischemic hindlimbs. The wound surface area, or lack of granulation tissue and exposed muscle, decreased daily in all mice, but was greater in the hrPEX mice by 12% to 16% (P< .004). Wounds in the control group were completely covered with granulation tissue by POD 3, whereas wounds injected with hrPEX2 were not completely covered by POD 7, but continued to have exposed muscle. Microscopic examination of wounds after PEX2-LV viral transduction, demonstrated an average epithelial gap of 1.6±0.3μm versus 0.64±0.3 μm in control wounds (P< .04). Wounds from Tie-2-GFP mice had an average number of 3.8±1.1 capillaries versus 6.9±1.2 in control wounds (P< .007).
Our study is the first report linking elevated PEX2 to ischemia and poor wound healing. We demonstrate comparative PEX2 elevation in ischemic murine hindlimbs. Wounds subjected to hrPEX2 or viral transduction with PEX2-LV produce less granulation tissue and retarded healing. Microscopic evaluation of the wounds exhibit fewer capillaries, supporting the hypothesis that PEX2 decreases angiogenesis.
For greenhouse gas (GHG) emissions by Beijing economy 2007, a concrete emission inventory covering carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) is presented and associated with an input-output analysis to reveal the local GHG embodiment in final demand and trade without regard to imported emissions. The total direct GHG emissions amount to 1.06E + 08 t CO2-eq, of which energy-related CO2 emissions comprise 90.49%, non-energy-related CO2 emissions 6.35%, CH4 emissions 2.33%, and N2O emissions 0.83%, respectively. In terms of energy-related CO2 emissions, the largest source is coal with a percentage of 53.08%, followed by coke with 10.75% and kerosene with 8.44%. Sector 26 (Construction Industry) holds the top local emissions embodied in final demand of 1.86E + 07 t CO2-eq due to its considerable capital, followed by energy-intensive Sectors 27 (Transport and Storage) and 14 (Smelting and Pressing of Ferrous and Nonferrous Metals). The GHG emissions embodied in Beijing's exports are 4.90E + 07 t CO2-eq, accounting for 46.01% of the total emissions embodied in final demand. The sound scientific database totally based on local emissions is an important basis to make effective environment and energy policies for local decision makers.
It remains unclear how speciation history might contribute to species-specific variation and affect species delimitation. We examined concordance between cytoplasmic genetic variation and morphological taxonomy in two fir species, Abies chensiensis and A. fargesii, with overlapping distributions in central China. Range-wide genetic variation was investigated using mitochondrial (mt) and plastid (pt) DNA sequences, which contrast in their rates of gene flow. Four mtDNA haplotypes were recovered and showed no obvious species' bias in terms of relative frequency. In contrast, a high level of ptDNA variation was recorded in both species with 3 common ptDNA haplotypes shared between them and 21 rare ptDNA haplotypes specific to one or other species. We argue that the lack of concordance between morphological and molecular variation between the two fir species most likely reflects extensive ancestral polymorphism sharing for both forms of cytoplasmic DNA variation. It is feasible that a relatively fast mutation rate for ptDNA contributed to the production of many species-specific ptDNA haplotypes, which remained rare due to insufficient time passing for their spread and fixation in either species, despite high levels of intraspecific ptDNA gene flow. Our phylogeographic analyses further suggest that polymorphisms in both organelle genomes most likely originated during and following glacial intervals preceding the last glacial maximum, when species distributions became fragmented into several refugia and then expanded in range across central China.
Abies chensiensis; A. fargesii; biogeography; gene flow; mutation rate; species delimitation
To select an appropriate prognostic model in the treatment of mature T- and natural killer (NK) -cell lymphoma (peripheral T-cell lymphoma (PTCL) and NK-/T-cell lymphoma (NKTCL)) is crucial. This study investigated the usefulness of Ann Arbor staging classification International prognostic index (IPI), prognostic index for T-cell lymphoma (PIT) and International peripheral T-cell lymphoma Project score (IPTCLP). Between 2000 and 2009, 176 patients (122 males) with PTCL and NKTCL were diagnosed and treated from a single institute in Taiwan. The correlation between complete response (CR) rate, 3-year overall survival (OS), early mortality rate and four prognostic models was analyzed. Thirty-one patients received hematopoietic stem cell transplantation (HSCT) and were analyzed separately. Three-year OS rate was 34.7%, and anaplastic large-cell lymphoma harbored better outcome than others. IPI score had the lowest Akaike information criterion value (1081.197) and was the best score in predicting OS and early mortality (P=0.009). Ann Arbor stage classification can predict CR rate more precisely (P=0.006). OS was significantly better in patients who received HSCT, even in patients with unfavorable features compared with chemotherapy alone. All prognostic models were useful to evaluate the outcome of patients with PTCL and NKTCL but IPI score did best in predicting OS in PTCL and PIT score in NKTCL. This study also supported the role of HSCT in patients with high-risk or refractory PTCL or NKTCL.
T-cell lymphoma; prognostic score; hematopoietic stem cell transplantation; Asian population
In this article, we propose a model selection method, the Bayesian composite model space approach, to map quantitative trait loci (QTL) in a half-sib population for continuous and binary traits. In our method, the identity-by-descent-based variance component model is used. To demonstrate the performance of this model, the method was applied to map QTL underlying production traits on BTA6 in a Chinese half-sib dairy cattle population. A total of four QTLs were detected, whereas only one QTL was identified using the traditional least square (LS) method. We also conducted two simulation experiments to validate the efficiency of our method. The results suggest that the proposed method based on a multiple-QTL model is efficient in mapping multiple QTL for an outbred half-sib population and is more powerful than the LS method based on a single-QTL model.
Bayesian model selection; variance component model; Markov chain Monte Carlo algorithm; QTL mapping
This article reviews experimental and modeling methods for determining the critical roles played by the various factors that control nanocarrier drug delivery to vascular endothelial cells.
Targeted drug delivery; nanocarriers; hemodynamics; binding; affinity
Tree reconstruction methods are often judged by their accuracy, measured by how close they get to the true tree. Yet, most reconstruction methods like maximum likelihood (ML) do not explicitly maximize this accuracy. To address this problem, we propose a Bayesian solution. Given tree samples, we propose finding the tree estimate that is closest on average to the samples. This “median” tree is known as the Bayes estimator (BE). The BE literally maximizes posterior expected accuracy, measured in terms of closeness (distance) to the true tree. We discuss a unified framework of BE trees, focusing especially on tree distances that are expressible as squared euclidean distances. Notable examples include Robinson–Foulds (RF) distance, quartet distance, and squared path difference. Using both simulated and real data, we show that BEs can be estimated in practice by hill-climbing. In our simulation, we find that BEs tend to be closer to the true tree, compared with ML and neighbor joining. In particular, the BE under squared path difference tends to perform well in terms of both path difference and RF distances.
Bayes estimator; consensus tree; path difference metric; phylogenetic inference
Hyperosmolar stress acts in two ways on the implanting embryo and its major constituent, placental trophoblast stem cells (TSC). Stress causes homeostasis that slows development with lesser cell accumulation, increased cell cycle arrest, and apoptosis. Stress may also cause placental differentiation at implantation. To test for the homeostatic and differentiation-inducing consequences of stress, TSC were exposed to hyperosmolar stress for 24hr and tested using whole mouse genome arrays and Real-time quantitative (Q)PCR. At 0.5hr, all 31 highly changing mRNA (>1.5-fold compared with unstressed TSC) decreased, but by 24hr 158/288 genes were upregulated. Many genes upregulated at 24hr were near baseline levels in unstressed TSC, suggesting new transcription. Thus few genes change during the early stress response, but by 24hr TSC have adapted to start new transcription with large gene sets. Types of genes upregulated at 24hr included homeostatic genes regulating growth and DNA damage induced (GADD45β/γ), activator protein (AP)-1 (junB/junC/ATF3/4), heat shock proteins (HSP22/68), and cyclin-dependent kinase inhibitor [CDKI; p15, p21]. But, stress also induced transcription factors that mediate TSC differentiation to trophoblast giant cells (TGC)(Stra13, HES1, GATA-binding2), placental hormones [proliferin, placental lactogen (PL)1, prolactin-like peptide (PLP)M], and extracellular matrix genes (CCN1/2). Transcription factors for later placental cell lineages, spongiotrophoblast (MASH2, TPBPα) and syncytiotrophoblast (GCM1, TEF5) and placental hormones (PLPA, PLII), were not induced by 24hr stress. Thus stress induced the temporal and spatial placental differentiation normal after implantation. Although differentiation was induced, markers of TSC stemness such as inhibitor of differentiation (ID)2 remained at 100% of levels of unstressed TSC, suggesting that retained mRNA might mediate dedifferentiation were stress to subside.
microarray; placental trophoblast stem cells; hyperosmolar stress; differentiation