The association between RhEPO and FN expression in glomerular mesangial cells

AIM

Erythropoietin (rhEPO) is increasingly being used in the treatment of anemia caused by miscellaneous reasons. The aim of our research is to investigate the effects of recombinant human erythropoietin (rhEPO) on cellular growth and fibronectin (FN) expression in glomerular mesangial cells.

METHODS

Western blot was used to detect the expression of FN induced by rhEPO (1, 10, 100 and 1000U/mL). In vivo studies, male CD-1 mice were administered rhEPO subcutaneously at a single dose of 1000U/Kg. The cellular hypertrophy was quantified by counting cell number and calculating the ratio of cell protein to cell number.

RESULTS

1) Compared with the control group, the results of mesangial cells' growth stimulated by rhEPO were not significantly different; 2) RhEPO lead to hypertrophy of mesangial cells; 3) rhEPO induced FN expression of mesangial cell in a dose-dependent way. Compared to control, 100U/mL rhEPO enhanced the expression of FN significantly; 4) indirect immunofluorescence showed that rhEPO induced large amount deposition of FN in the intercellular space of mesangial cells; 5) in vivo studies, there were markedly increase of FN expression in mice received the injection of rhEPO.

CONCLUSION

RhEPO could up-regulated the expression of FN and induced glomerular mesangial cells hypertrophy. These results suggested rhEPO could induce dysfunction of renal glomerulus through its influence on the function of mesangial cells.

Radiological findings in 210 paediatric patients with viral pneumonia: a retrospective case study

OBJECTIVE

The objective of this study was to assess the radiological presentations of different types of viral pneumonia in children.

METHODS

Nasopharyngeal swab specimens and bronchial aspirate samples from children with acute respiratory infections were obtained and tested for influenza B, adenovirus, respiratory syncytial virus and parainfluenza (Types 1, 2 and 3) by direct immunofluorescence assay, or for influenza A (Subtype H1N1) by quantitative real-time polymerase chain reaction. The chest radiographs of the 210 confirmed cases of viral pneumonia were analysed retrospectively by two independent radiologists for the identification, characterisation and description of the distribution of imaging abnormalities. The cases were divided into six groups on the basis of confirmed causative viral agent, and radiographic findings were compared, analysed and presented.

RESULTS

The abnormal chest radiograph findings consisted of bilateral patchy areas of consolidation (n=133), interstitial lung disease (n=33), diffuse areas of air space consolidation (n=29) and lobar consolidation (n=15). The abnormalities were distributed bilaterally in 195 cases and observed more frequently in the lower zones than in other regions. The radiological findings varied significantly among the six groups (p=0.0050). Pairwise comparison showed significant difference between influenza A (H1N1) and adenovirus (p=0.0031) only.

CONCLUSION

The predominant radiological finding in paediatric viral pneumonia was bilateral patchy areas of consolidation. The radiological findings differed significantly only between adenovirus and influenza A pneumonia. The diagnosis of the specific causative organism requires laboratory confirmation.

Experimental verification of the chemical sensitivity of two-site double core-hole states formed by an x-ray free-electron laser

We have performed x-ray two-photon photoelectron spectroscopy using the Linac Coherent Light Source x-ray free-electron laser in order to study double core-hole (DCH) states of CO2, N2O, and N2. The experiment verifies the theory behind the chemical sensitivity of two-site DCH states by comparing a set of small molecules with respect to the energy shift of the two-site DCH state and by extracting the relevant parameters from this shift.

MiR-1 and miR-200 inhibit EMT via Slug-dependent and tumorigenesis via Slug-independent mechanisms

Epithelial-mesenchymal transition (EMT) is a developmental program of signaling pathways that determine commitment to epithelial and mesenchymal phenotypes. In the prostate, EMT processes have been implicated in benign prostatic hyperplasia and prostate cancer progression. In a model of Pten- and TP53-null prostate adenocarcinoma that progresses via transforming growth factor β-induced EMT, mesenchymal transformation is characterized by plasticity, leading to various mesenchymal lineages and the production of bone. Here we show that SLUG is a major regulator of mesenchymal differentiation. As microRNAs (miRs) are pleiotropic regulators of differentiation and tumorigenesis, we evaluated miR expression associated with tumorigenesis and EMT. Mir-1 and miR-200 were reduced with progression of prostate adenocarcinoma, and we identify Slug as one of the phylogenetically conserved targets of these miRs. We demonstrate that SLUG is a direct repressor of miR-1 and miR-200 transcription. Thus, SLUG and miR-1/miR-200 act in a self-reinforcing regulatory loop, leading to amplification of EMT. Depletion of Slug inhibited EMT during tumorigenesis, whereas forced expression of miR-1 or miR-200 inhibited both EMT and tumorigenesis in human and mouse model systems. Various miR targets were analyzed, and our findings suggest that miR-1 has roles in regulating EMT and mesenchymal differentiation through Slug and functions in tumor-suppressive programs by regulating additional targets.

Unveiling and driving hidden resonances with high-fluence, high-intensity x-ray pulses

We show that high fluence, high-intensity x-ray pulses from the world's first hard x-ray free-electron laser produce nonlinear phenomena that differ dramatically from the linear x-ray-matter interaction processes that are encountered at synchrotron x-ray sources. We use intense x-ray pulses of sub-10-fs duration to first reveal and subsequently drive the 1s↔2p resonance in singly ionized neon. This photon-driven cycling of an inner-shell electron modifies the Auger decay process, as evidenced by line shape modification. Our work demonstrates the propensity of high-fluence, femtosecond x-ray pulses to alter the target within a single pulse, i.e., to unveil hidden resonances, by cracking open inner shells energetically inaccessible via single-photon absorption, and to consequently trigger damaging electron cascades at unexpectedly low photon energies.

Polymorphisms of caprine POU1F1 gene and their association with litter size in Jining Grey goats

Seven pairs of primers were designed to amplify 5' promoter region, six exons and partial introns and to detect the polymorphisms of POU1F1 gene in five goat breeds with different prolificacy. The results showed that six mutations were identified in caprine POU1F1 gene including C256T in exon 3, C53T and T123G in intron 3, and G682T (A228S), T723G and C837T in exon 6. The former four mutations were novel SNPs in goat POU1F1 gene. The 53 and 123 loci were in complete linkage disequilibrium in five caprine breeds. Regarding the 256 locus, the Jining Grey goat does with genotype CT had 0.66 kids more than those with genotype CC (P < 0.05), while does with genotype GT had 0.63 (P < 0.05) kids more than those with genotype GG at the 682 locus. The present study preliminarily showed an association between allele T at the 256 and 682 loci of POU1F1 gene and high litter size in Jining Grey goats. Totally 16 haplotypes and 50 genotypes were identified at the above six loci in POU1F1 gene of five goat breeds. Three common haplotypes (hap2, hap3 and hap4) were identified in five goat breeds joined. Four specific haplotypes (hap7, hap9, hap11 and hap13) were detected in Jining Grey goats. The predominant haplotype was hap1 (35.29% and 48.25%) in both Jining Grey and Guizhou White goats, while hap4 (50%) in Boer goats, and hap2 (42.86% and 38.75%) in both Wendeng Dairy and Liaoning Cashmere goats. The most frequent genotypes at six loci in the above five goat breeds were hap1/hap2 (14.38%) and hap1/hap4 (14.38%), hap1/hap2 (38.60%), hap4/hap4 (40.91%), hap2/hap4 (26.53%), hap2/hap5 (20.00%), respectively. The Jining Grey goat does with nine genotypes analyzed of POU1F1 gene showed no obvious difference in litter size.

Predictive potential of microsatellite markers on heterosis of fecundity in crossbred sheep

Small Tail Han (STH) sheep is a famous Chinese local breed and has perfect prolificacy performance, but it is inferior to imported mutton sheep breeds on meat production. In this study, six imported male sheep populations (White Suffolk, Black Suffolk, Texel, Dorper, South African Mutton Merino and East Friesian) were crossbred with STH female sheep respectively. The heterosis values of litter size, average daily gain (ADG) and feed conversion ratio (FCR) of crossbred sheep were analyzed for seeking the optimal cross. Meanwhile 28 microsatellite markers were used to measure the genetic distance between imported populations and STH population. Regression between the genetic distance and heterosis was analyzed for evaluating potential of microsatellite on predicting heterosis. Results showed a significant positive linear correlation (r = 0.892, P < 0.05) between heterosis of litter size and genetic distance D (A) of six crosses. This implied that these microsatellite markers had moderate potential to forecast heterosis of litter size in sheep. Results of this study also indicated that South African Mutton Merino and East Friesian sheep would be the optimal sire breeds for the litter size and might bring the greatest economic benefit in six imported populations; Suffolk sheep could be prior consideration as sire breeds when breeding objective focused on ADG. Finally these results provided valuable information for Chinese sheep industry.

Myocardial oxidative stress contributes to transgenic β₂-adrenoceptor activation-induced cardiomyopathy and heart failure

BACKGROUND AND PURPOSE

While maintaining cardiac performance, chronic β-adrenoceptor activation eventually exacerbates the progression of cardiac remodelling and failure. We examined the adverse signalling pathways mediated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and reactive oxygen species (ROS) after chronic β₂-adrenoceptor activation.

EXPERIMENTAL APPROACH

Mice with transgenic β₂-adrenoceptor overexpression (β₂-TG) and non-transgenic littermates were either untreated or treated with an antioxidant (N-acetylcysteine, NAC) or NADPH oxidase inhibitors (apocynin, diphenyliodonium). Levels of ROS, phosphorylated p38 mitogen-activated protein kinase (MAPK), pro-inflammatory cytokines and collagen content in the left ventricle (LV) and LV function were measured and compared.

KEY RESULTS

β₂-TG mice showed increased ROS production, phosphorylation of p38 MAPK and heat shock protein 27 (HSP27), expression of pro-inflammatory cytokines and collagen, and progressive ventricular dysfunction. β₂-adrenoceptor stimulation similarly increased ROS production and phosphorylation of p38 MAPK and HSP27 in cultured cardiomyocytes. Treatment with apocynin, diphenyliodonium or NAC reduced phosphorylation of p38 MAPK and HSP27 in both cultured cardiomyocytes and the LV of β₂-TG mice. NAC treatment (500 mg·kg⁻¹ ·day⁻¹) for 2 weeks eliminated the up-regulated expression of pro-inflammatory cytokines and collagen in the LV of β₂-TG mice. Chronic NAC treatment to β₂-TG mice from 7 to 10 months of age largely prevented progression of ventricular dilatation, preserved contractile function (fractional shortening 37 ± 5% vs. 25 ± 3%, ejection fraction 52 ± 5% vs. 32 ± 4%, both P < 0.05), reduced cardiac fibrosis and suppressed matrix metalloproteinase activity.

CONCLUSION AND IMPLICATIONS

β₂-adrenoceptor stimulation provoked NADPH oxidase-derived ROS production in the heart. Elevated ROS activated p38 MAPK and contributed significantly to cardiac inflammation, remodelling and failure.

Nonlinear atomic response to intense ultrashort x rays

The nonlinear absorption mechanisms of neon atoms to intense, femtosecond kilovolt x rays are investigated. The production of Ne(9+) is observed at x-ray frequencies below the Ne(8+), 1s(2) absorption edge and demonstrates a clear quadratic dependence on fluence. Theoretical analysis shows that the production is a combination of the two-photon ionization of Ne(8+) ground state and a high-order sequential process involving single-photon production and ionization of transient excited states on a time scale faster than the Auger decay. We find that the nonlinear direct two-photon ionization cross section is orders of magnitude higher than expected from previous calculations.

GDF9 as a candidate gene for prolificacy of Small Tail Han sheep

Growth differentiation factor 9 (GDF9) which controls the fecundity of Belclare, Cambridge, Santa Ines, Moghani, Ghezel and Thoka ewes was studied as a candidate gene for the prolificacy of Small Tail Han sheep. According to the sequence of ovine GDF9 gene, six pairs of primers were designed to detect single nucleotide polymorphisms of two exons of GDF9 gene in both high fecundity breed (Small Tail Han sheep) and low fecundity breed (Dorset sheep) by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). Only the products amplified by primers 2-1 and 2-2 displayed polymorphisms. For primer 2-1, three genotypes (AA, AB and BB) were detected in both sheep breeds. Sequencing revealed one silent mutation (G477A) in exon 2 of GDF9 gene in the BB genotype in comparison with the AA, which was known as G3 mutation of GDF9 gene in Belclare and Cambridge ewes. The relationship of least squares means for litter size was AA > AB > BB in Small Tail Han sheep (P > 0.05). For primer 2-2, two genotypes (CC and CD) were detected in both sheep breeds. Sequencing revealed one novel single nucleotide mutation (G729T) in exon 2 of GDF9 gene in the CD genotype in comparison with the CC, which resulted in an amino acid change (Gln243His). The ewes with mutation heterozygous genotype CD had 0.77 (P < 0.01) lambs more than those with wild type CC in Small Tail Han sheep. These results preliminarily indicated that allele D of GDF9 gene was a potential genetic marker for improving litter size in Small Tail Han sheep.

Analysis on DNA sequence of GPR54 gene and its association with litter size in goats

The kisspeptin/GPR54 pathway is crucial in the process of puberty onset. Six pairs of primers were designed to clone goat GPR54 and scan polymorphisms and one pair of primers to detect polymorphisms of GPR54 in sexual precocious and sexual late-maturing goat breeds. A DNA fragment of 4258 bp of goat GPR54 was obtained, which contains an open reading frame (ORF) of 1137 bp and encodes 378 amino acids, having a high homology with other mammals. The protein was predicted to have seven transmembrane regions. There were no base pair variation in exons 1-4 and three base changes (G4014A, G4136A and C4152T) in exon 5 by sequencing and the three mutations may have some correlation with sexual precocity in goats. For the 4152 locus, the Jining Grey goat does with genotype TT and CT had 1.02 and 0.84 (P<0.01) kids more than those with genotype CC, respectively. No significant difference (P>0.05) was found in litter size between TT and CT genotypes in Jining Grey goat. For the other two loci, no significant difference (P>0.05) was found in litter size between different genotypes in Jining Grey goats. The present study preliminarily indicated an association between allele T of the 4152 locus in GPR54 and high litter size in Jining Grey goats.

MicroRNA miR-93 promotes tumor growth and angiogenesis by targeting integrin-β8

It has been reported that the miR-106b∼25 cluster, a paralog of the miR-17∼92 cluster, possesses oncogenic activities. However, the precise role of each microRNA (miRNA) in the miR-106b∼25 cluster is not yet known. In this study, we examined the function of miR-93, one of the microRNAs within the miR-106b∼25 cluster, in angiogenesis and tumor formation. We found that miR-93 enhanced cell survival, promoted sphere formation and augmented tumor growth. Most strikingly, when miR-93-overexpressing U87 cells were co-cultured with endothelial cells, they supported endothelial cell spreading, growth, migration and tube formation. In vivo studies revealed that miR-93-expressing cells induced blood vessel formation, allowing blood vessels to extend to tumor tissues in high densities. Angiogenesis promoted by miR-93 in return facilitated cell survival, resulting in enhanced tumor growth. We further showed that integrin-β8 is a target of miR-93. Higher levels of integrin-β8 are associated with cell death in tumor mass and in human glioblastoma. Silencing of integrin-β8 expression using small interfering RNA promoted cell proliferation, whereas ectopic expression of integrin-β8 decreased cell growth. These findings showed that miR-93 promotes tumor growth and angiogenesis by suppressing, at least in part, integrin-β8 expression. Our results suggest that inhibition of miR-93 function may be a feasible approach to suppress angiogenesis and tumor growth.

Auger electron angular distribution of double core-hole states in the molecular reference frame

The Linac Coherent Light Source free electron laser is a source of high brightness x rays, 2×10(11) photons in a ∼5 fs pulse, that can be focused to produce double core vacancies through rapid sequential ionization. This enables double core vacancy Auger electron spectroscopy, an entirely new way to study femtosecond chemical dynamics with Auger electrons that probe the local valence structure of molecules near a specific atomic core. Using 1.1 keV photons for sequential x-ray ionization of impulsively aligned molecular nitrogen, we observed a rich single-site double core vacancy Auger electron spectrum near 413 eV, in good agreement with ab initio calculations, and we measured the corresponding Auger electron angle dependence in the molecular frame.

Double core-hole production in N2: beating the Auger clock

We investigate the creation of double K-shell holes in N2 molecules via sequential absorption of two photons on a time scale shorter than the core-hole lifetime by using intense x-ray pulses from the Linac Coherent Light Source free electron laser. The production and decay of these states is characterized by photoelectron spectroscopy and Auger electron spectroscopy. In molecules, two types of double core holes are expected, the first with two core holes on the same N atom, and the second with one core hole on each N atom. We report the first direct observations of the former type of core hole in a molecule, in good agreement with theory, and provide an experimental upper bound for the relative contribution of the latter type.

Time-resolved pump-probe experiments at the LCLS

The first time-resolved x-ray/optical pump-probe experiments at the SLAC Linac Coherent Light Source (LCLS) used a combination of feedback methods and post-analysis binning techniques to synchronize an ultrafast optical laser to the linac-based x-ray laser. Transient molecular nitrogen alignment revival features were resolved in time-dependent x-ray-induced fragmentation spectra. These alignment features were used to find the temporal overlap of the pump and probe pulses. The strong-field dissociation of x-ray generated quasi-bound molecular dications was used to establish the residual timing jitter. This analysis shows that the relative arrival time of the Ti:Sapphire laser and the x-ray pulses had a distribution with a standard deviation of approximately 120 fs. The largest contribution to the jitter noise spectrum was the locking of the laser oscillator to the reference RF of the accelerator, which suggests that simple technical improvements could reduce the jitter to better than 50 fs.

Femtosecond electronic response of atoms to ultra-intense X-rays

An era of exploring the interactions of high-intensity, hard X-rays with matter has begun with the start-up of a hard-X-ray free-electron laser, the Linac Coherent Light Source (LCLS). Understanding how electrons in matter respond to ultra-intense X-ray radiation is essential for all applications. Here we reveal the nature of the electronic response in a free atom to unprecedented high-intensity, short-wavelength, high-fluence radiation (respectively 10(18) W cm(-2), 1.5-0.6 nm, approximately 10(5) X-ray photons per A(2)). At this fluence, the neon target inevitably changes during the course of a single femtosecond-duration X-ray pulse-by sequentially ejecting electrons-to produce fully-stripped neon through absorption of six photons. Rapid photoejection of inner-shell electrons produces 'hollow' atoms and an intensity-induced X-ray transparency. Such transparency, due to the presence of inner-shell vacancies, can be induced in all atomic, molecular and condensed matter systems at high intensity. Quantitative comparison with theory allows us to extract LCLS fluence and pulse duration. Our successful modelling of X-ray/atom interactions using a straightforward rate equation approach augurs favourably for extension to complex systems.

Ultraintense x-ray induced ionization, dissociation, and frustrated absorption in molecular nitrogen

Sequential multiple photoionization of the prototypical molecule N2 is studied with femtosecond time resolution using the Linac Coherent Light Source (LCLS). A detailed picture of intense x-ray induced ionization and dissociation dynamics is revealed, including a molecular mechanism of frustrated absorption that suppresses the formation of high charge states at short pulse durations. The inverse scaling of the average target charge state with x-ray peak brightness has possible implications for single-pulse imaging applications.

Validity of Proxy Data Obtained by Different Psychological Autopsy Information Reconstruction Techniques

Two informants were interviewed for each of 416 living controls (individuals sampled from the normal population) interviewed in a Chinese case–control psychological autopsy study. The validity of proxy data, obtained using seven psychological autopsy information reconstruction techniques (types 1, 2 and A – E), was evaluated, with living controls' self reports used as the gold-standard. Proxy data for reconstruction technique types 1, 2 and D on the Impulsivity Inventory Scale (total impulsivity score) were no different from the living controls' self report gold standard, whereas data for types A and E were smaller than data from living controls. On the ‘acceptance or resignation’ sub-scale of the avoidance coping dimension of the Moos Coping Response Inventory, information obtained by reconstruction technique types 1 and D was not significantly different from the living controls' self reports, whereas proxy data from types 2, A and E were smaller than those from the living controls. No statistically significant differences were identified for other proxy data obtained by reconstruction technique types 1, 2, A, D and E. These results indicate that using a second informant does not significantly enhance information reconstruction for the target.