Targeting thioredoxin-1 with siRNA exacerbates oxidative stress injury after cerebral ischemia/reperfusion in rats

Reactive oxygen species and their detrimental effects on the brain after transient ischemia/reperfusion (I/R) have been implicated in the pathogenesis of ischemic reperfusion injury. Thioredoxin-1 (Trx-1) is an endogenous antioxidant protein that has neuroprotective effects. We hypothesized that Trx-1 plays a crucial role in regulating cerebral I/R injury. To be able to test this, 190 Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion (tMCAO) with Trx-1 siRNA (small interference RNA) injected 24 h prior to ischemia. At 24 h after tMCAO, we measured neurological deficits, infarct volume, and brain water content, and found that neurological dysfunction, brain infarct size, and brain edema were worse in the Trx-1 siRNA group than in the control group. Oxidative stress was evaluated by measuring superoxide dismutase activity and malondialdehyde level. The levels of Trx-1 and its cofactor, peroxiredoxin (Prdx), were significantly decreased after Trx-1 down-regulated. However, there is no significant difference in the Prdx mRNA level after administration of Trx-1 siRNA. In contrast, Prdx-SO3 protein levels were significantly increased in the Trx-1 siRNA group. We also investigated the specific role of nuclear factor erythroid 2-related factor 2 (Nrf2) in Trx-1 induction by knocking down Nrf2. Nrf2 siRNA injection decreased Trx-1 mRNA and protein expression. Our results suggest that the exacerbation of brain damage was associated with enhanced cerebral peroxidation in brain tissues. Moreover, these results revealed that Trx-1, which is more likely regulated by Nrf2, exerts a neuroprotective role probably through maintaining the reduction activity of Prdx1-4.

Carbon Black Reinforced Thermoplastic Vulcanizates Based on High Impact Polystyrene/Styrene-Butadiene-Styrene Block Copolymer/Styrene-Butadiene Rubber Blends

Thermoplastic vulcanizates (TPVs) based on high impact polystyrene (HIPS)/styrene-butadiene-styrene block copolymer (SBS)/styrene-butadiene rubber (SBR) blends were prepared by dynamic vulcanization, with the TPVs being reinforced by carbon black (CB). Experimental results indicated that mechanical properties of dynamically vulcanized HIPS/SBS/SBR blends were enhanced remarkably by the incorporation of CB. The fracture surface morphology of the reinforced HIPS/SBS/SBR/CB TPVs was relatively flat. The Mullins effect could be observed in the stress-strain curves of HIPS/SBS/SBR TPVs and HIPS/SBS/SBR/CB TPVs during the uniaxial loading-unloading cycles. Compared with HIPS/SBS/SBR TPVs, CB-reinforced HIPS/SBS/SBR TPVs had the relatively higher stress, residual strain and internal friction loss.

Supplementing antioxidants to pigs fed diets high in oxidants: I. Effects on growth performance, liver function, and oxidative status

The objective of the study was to determine the effects of a dietary antioxidant blend (ethoxyquin and propyl gallate) and vitamin E on growth performance, liver function, and oxidative status in pigs fed diets high in oxidants. Crossbred barrows (n=100, 10.91±0.65 kg BW, 36±2 d of age, Landrace×Duroc) were allotted to 5 treatments on the basis of BW (5 replicate pens per treatment, 4 pigs per pen). Treatments included 1) HO, high-oxidant diet containing 5% oxidized soybean oil and 10% PUFA source (providing 2.05% docosahexaenoic acid in the diet), 2) VE, the HO diet with 11 IU/kg of added vitamin E, 3) AOX, the HO diet with antioxidant blend (135 mg/kg), 4) VE+AOX, the HO diet with both vitamin E and antioxidant blend, and 5) SC, a standard corn-soy control diet. The trial lasted for 118 d; on d 83, the HO diet pigs were switched to the SC diet because the animals were displaying very poor health. Compared with SC pigs, HO pigs had decreased ADG (0.92 vs. 0.51 kg for d 26 to 55, 1.29 vs. 0.34 kg for d 56 to 82; P<0.05) and ADFI (1.84 vs. 0.96 kg for d 26 to 55, 3.41 vs. 1.14 kg for d 56 to 82; P<0.05). However, switching the HO pigs to the SC diet resulted in HO pigs having a greater ADG than VE-fed pigs from d 83 to 118 (0.90 vs. 0.60 kg; P<0.05). The antioxidant blend restored pig performance to a level similar that of pigs fed the SC diet (P>0.05) with greater G:F for the entire period (0.44 vs. 0.38; P<0.05). A greater liver to BW ratio was found in HO compared with other treatments on d 55 and in VE on d 118. Total bilirubin concentration in plasma of HO pigs on d 55 was greater than that in VE+AOX pigs (P<0.05), whereas on d 118, bilirubin concentration in VE was higher than those in VE+AOX and SC (P<0.05). A similar trend was observed in aspartate transaminase. Plasma concentrations of thiobarbituric acid reactive substances (TBARS) and carbonyl were elevated (P<0.05) in the HO pigs compared with the SC pigs on d 55 but not on d 118. Liver TBARS and carbonyl concentrations showed a similar trend, except that HO pigs had the greatest carbonyl concentration on d 118. Pigs fed AOX diets had plasma and liver TBARS and carbonyl concentrations similar to those fed SC diets. In the oxidative stress model used in this study, dietary addition of antioxidant blend or antioxidant blend+vitaimin E was effective in improving growth, liver function, and plasma markers of oxidative stress, but VE alone was not.

Clinical and laboratory characteristics of systemic sclerosis patients with pulmonary arterial hypertension in China

OBJECTIVES

Pulmonary arterial hypertension (PAH) is associated with significant morbidity and mortality, especially in systemic sclerosis (SSc). Since there was no published study regarding PAH in the Chinese SSc population, we aimed to describe a cohort to provide some data for early diagnosis.

METHODS

We evaluated 236 systemic sclerosis patients prospectively registered in the EUSTAR (European League Against Rheumatism Scleroderma Trial and Research Group) database from the Peking Union Medical College Hospital from 2009 to 2012. Among them, 33 individuals received right heart catheterisations (RHC) while the remaining patients were grouped by echocardiographic data. These patients were classified into two groups, PAH and non-PAH group. Their clinical and laboratory features were statistically analysed to identify possible risk factors for PAH in Chinese SSc population.

RESULTS

The possible prevalence of PAH in SSc patients was approximately 11% in our study. Digital ulcers (52.0% vs. 31.2%), telangiectasias (64.0% vs. 37.6%) and gastroesophageal reflux disease (GERD) (60.0% vs. 36.2%) were more common in SSc patients with PAH. Some laboratory results were also proved to be significantly correlated with it. Logistic regression analysis showed that telangiectasias (OR=2.888, 95% CI=1.176-7.093), presence of GERD (OR=2.592, 95% CI=1.067-6.296), anti-RNP positivity (OR=24.384, 95% CI=1.978-36.651), IgA level elevation (OR=8.745, 95% CI 4.838-122.896) and FVC/TLCO ratio (OR=97.067, 95% CI 12.475-755.271) were associated with an increased odds for PAH in SSc patients.

CONCLUSIONS

This study described possible predictors of PAH in Chinese SSc population, which have been supported by similar studies in other ethnic groups.

Graphene-based polyaniline arrays for deoxyribonucleic acid electrochemical sensor: effect of nanostructure on sensitivity

DNA detection sensitivity can be improved by carefully controlling the texture of the sensor substrate, which was normally investigated on metal or metal oxide nanostructured platform. Morphology effects on the biofunctionalization of polymer micro/nanoelectrodes have not been investigated in detail. To extend this topic, we used graphene oxide (GNO) as the supporting material to prepare graphene-based polyaniline nanocomposites with different morphologies as a model for comparing their DNA sensing behaviors. Owing to GNO serving as an excellent support or template for nucleation and growth of polyaniline (PANI), PANI nanostructures grown on GNO substrate were successfully obtained. However, if GNO supporting was absent, the obtained PANI nanowires showed a connected network. Furthermore, adjustment of reaction time can be used for dominating the topographies of PANI-GNO nanocomposites, meaning that different reaction times resulted in various formations of PANI-GNO nanocomposites, including small horns (5 and 12 h), vertical arrays (18 h), and nanotips (24 h). The next-step electrochemical data showed that the DNA electrochemical sensors constructed on the different morphologies possessed different ssDNA surface coverage and hybridization efficiency. Compared with other morphologies of PANI-GNO nanocomposite (5, 12, and 24 h), vertical arrays (18 h) exhibited the highest sensitivity (2.08 × 10(-16) M, 2 orders of magnitude lower than others). It is can be concluded that this nanocomposite with higher surface area and more accessible space can provide an optimal balance for DNA immobilization and DNA hybridization detection.

Above- and below-ground carbon stocks in an indigenous tree (Mytilaria laosensis) plantation chronosequence in subtropical China

More than 60% of the total area of tree plantations in China is in subtropical, and over 70% of subtropical plantations consist of pure stands of coniferous species. Because of the poor ecosystem services provided by pure coniferous plantations and the ecological instability of these stands, a movement is under way to promote indigenous broadleaf plantation cultivation as a promising alternative. However, little is known about the carbon (C) stocks in indigenous broadleaf plantations and their dependence on stand age. Thus, we studied above- and below-ground biomass and C stocks in a chronosequence of Mytilaria laosensis plantations in subtropical China; stands were 7, 10, 18, 23, 29 and 33 years old. Our assessments included tree, shrub, herb and litter layers. We used plot-level inventories and destructive tree sampling to determine vegetation C stocks. We also measured soil C stocks by analyses of soil profiles to 100 cm depth. C stocks in the tree layer dominated the above-ground ecosystem C pool across the chronosequence. C stocks increased with age from 7 to 29 years and plateaued thereafter due to a reduction in tree growth rates. Minor C stocks were found in the shrub and herb layers of all six plantations and their temporal fluctuations were relatively small. C stocks in the litter and soil layers increased with stand age. Total above-ground ecosystem C also increased with stand age. Most increases in C stocks in below-ground and total ecosystems were attributable to increases in soil C content and tree biomass. Therefore, considerations of C sequestration potential in indigenous broadleaf plantations must take stand age into account.

Genetic diversity and expression profiles of cysteine phytases in the sheep rumen during a feeding cycle

Cysteine phytase is the main phytate-degrading enzyme of ruminant animals. To explore the genetic diversity and dynamic expression profile of cysteine phytase in sheep rumen during a feeding cycle, four transcript (0, 4, 9 and 16 h after feeding) and one DNA (9 h after feeding) clone libraries were constructed, respectively. A total of 46 distinct gene fragments were identified, and most of these sequences had low identities (<60%) with known phytases. Great divergence was found in the constitution and abundance of genes at the genome and transcriptional levels, and the transcript data are more reliable to reflect the information of functional genes. Phylogenetic analysis indicated that the genes from uncultured bacteria instead of Firmicutes played the major phytate-degrading role. Further comparative analysis revealed the dynamic constitution of cysteine phytase genes in rumen at different time points.

SIGNIFICANCE AND IMPACT OF THE STUDY

Ruminal phytases, that are cysteine phytases, are novel in sequences and functions. Great divergence in the constitution and abundance of cysteine phytase genes at the genome and transcriptional levels suggested that transcript data are more reliable to reflect the information of functional genes. Phylogenetic and rarefaction analyses indicated that the cysteine phytase genes from uncultured bacteria instead of Firmicutes play the major phytate-degrading role in rumen, and their constitution is dynamic at different time points. This study provides a new insight into ruminal cysteine phytase genes and undermines their expression profiles over a whole feeding cycle.

Observation of D0 meson nuclear modifications in Au+Au collisions at sqrt[s(NN)] = 200 GeV

We report the first measurement of charmed-hadron (D(0)) production via the hadronic decay channel (D(0) → K(-) + π(+)) in Au+Au collisions at sqrt[s(NN)] = 200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, N(bin), from p+p to central Au+Au collisions. The D(0) meson yields in central Au + Au collisions are strongly suppressed compared to those in p+p scaled by N(bin), for transverse momenta p(T) > 3 GeV/c, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate p(T) is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements.

Search for a light sterile neutrino at Daya Bay

A search for light sterile neutrino mixing was performed with the first 217 days of data from the Daya Bay Reactor Antineutrino Experiment. The experiment's unique configuration of multiple baselines from six 2.9 GW(th) nuclear reactors to six antineutrino detectors deployed in two near (effective baselines 512 m and 561 m) and one far (1579 m) underground experimental halls makes it possible to test for oscillations to a fourth (sterile) neutrino in the 10(-3) eV(2)<|Δm(41)(2) |< 0.3 eV(2) range. The relative spectral distortion due to the disappearance of electron antineutrinos was found to be consistent with that of the three-flavor oscillation model. The derived limits on sin(2) 2θ(14) cover the 10(-3) eV(2) ≲ |Δm(41)(2)| ≲ 0.1 eV(2) region, which was largely unexplored.

Active and passive heat stress similarly compromise tolerance to a simulated hemorrhagic challenge

Passive heat stress increases core and skin temperatures and reduces tolerance to simulated hemorrhage (lower body negative pressure; LBNP). We tested whether exercise-induced heat stress reduces LBNP tolerance to a greater extent relative to passive heat stress, when skin and core temperatures are similar. Eight participants (6 males, 32 ± 7 yr, 176 ± 8 cm, 77.0 ± 9.8 kg) underwent LBNP to presyncope on three separate and randomized occasions: 1) passive heat stress, 2) exercise in a hot environment (40°C) where skin temperature was moderate (36°C, active 36), and 3) exercise in a hot environment (40°C) where skin temperature was matched relative to that achieved during passive heat stress (∼38°C, active 38). LBNP tolerance was quantified using the cumulative stress index (CSI). Before LBNP, increases in core temperature from baseline were not different between trials (1.18 ± 0.20°C; P > 0.05). Also before LBNP, mean skin temperature was similar between passive heat stress (38.2 ± 0.5°C) and active 38 (38.2 ± 0.8°C; P = 0.90) trials, whereas it was reduced in the active 36 trial (36.6 ± 0.5°C; P ≤ 0.05 compared with passive heat stress and active 38). LBNP tolerance was not different between passive heat stress and active 38 trials (383 ± 223 and 322 ± 178 CSI, respectively; P = 0.12), but both were similarly reduced relative to active 36 (516 ± 147 CSI, both P ≤ 0.05). LBNP tolerance is not different between heat stresses induced either passively or by exercise in a hot environment when skin temperatures are similarly elevated. However, LBNP tolerance is influenced by the magnitude of the elevation in skin temperature following exercise induced heat stress.

Data mining and frequency analysis for licorice as a "Two-Face" herb in Chinese Formulae based on Chinese Formulae Database

Liquorice is the root of Glycyrrhiza uralensis Fisch. or Glycyrrhiza glabra L., Leguminosae. Licorice is described as 'National Venerable Master' in Chinese medicine and plays paradoxical roles, i.e. detoxification/strengthen efficacy and inducing/enhancing toxicity. Therefore, licorice was called "Two-Face" herb in this paper. The aim of this study is to discuss the paradoxical roles and the perspective usage of this "Two-Face" herb using data mining and frequency analysis. More than 96,000 prescriptions from Chinese Formulae Database were selected. The frequency and the prescription patterns were analyzed using Microsoft SQL Server 2000. Data mining methods (frequent itemsets) were used to analyze the regular patterns and compatibility laws of the constituent herbs in the selected prescriptions. The result showed that licorice (Radix glycyrrhizae) was the most frequently used herb in Chinese Formulae Database, other frequently used herbs including Radix Angelicae Sinensis (Dang gui), Radix et rhizoma ginseng (Ren shen), etc. Toxic herbs such as Radix aconiti lateralis praeparata (Fu zi), Rhizoma pinelliae (Ban xia) and Cinnabaris (Zhu sha) are top 3 herbs that most frequently used in combination with licorice. Radix et rhizoma ginseng (Ren shen), Poria (Fu ling), Radix Angelicae Sinensis (Dang gui) are top 3 nontoxic herbs that most frequently used in combination with licorice. Moreover, Licorice was seldom used with sargassum (Hai Zao), Herba Cirsii Japonici (Da Ji), Euphorbia kansui (Gan Sui) and Flos genkwa (Yuan Hua), which proved the description of contradictory effect of Radix glycyrrhizae and these herbs as recorded in Chinese medicine theory. This study showed the principle pattern of Chinese herbal drugs used in combination with licorice or not. The principle patterns and special compatibility laws reported here could be useful and instructive for scientific usage of licorice in clinic application. Further pharmacological and chemical researches are needed to evaluate the efficacy and the combination pattern of these Chinese herbs. The mechanism of the combination pattern of these prescriptions should also be investigated whether additive, synergistic or antagonistic effect exist using in vitro or in vivo models.

Broadly wavelength tunable acousto-optically Q-switched Tm:Lu2SiO5 laser

A broadly wavelength tunable acousto-optically Q-switched Tm:Lu2SiO5 (Tm:LSO) laser is presented for the first time, to our best knowledge. The emission wavelength was tuned in a broad spectral region over 111 nm ranging from 1959 to 2070 nm. A shortest pulse duration of 345 ns with beam quality of M(2)≤1.65 was obtained at pulse repetition frequency (PRF) of 1 kHz, corresponding to a maximum single pulse energy of 0.26 mJ and peak power of 0.75 kW. The experimental results indicated that Tm:LSO crystal has outstanding potential for obtaining broadly wavelength tunable and low-PRF laser pulses at 2 μm.

Effect of functional nuclear factor-kappaB genetic polymorphisms on hepatitis B virus persistence and their interactions with viral mutations on the risk of hepatocellular carcinoma

BACKGROUND

Nonresolving inflammation and viral mutations are important in hepatitis B virus (HBV)-induced hepatocarcinogenesis. However, the effects of genetic polymorphisms affecting nuclear factor-kappaB (NF-κB) on HBV persistence and generation of hepatocellular carcinoma (HCC)-related HBV mutations remain unknown.

PATIENTS AND METHODS

rs28362491 (NFKB1 -94Ins > Del), rs2233406 (NFKBIA -826C > T), rs3138053 (NFKBIA -881A > G), and rs696 (NFKBIA +2758G > A) were genotyped in 1342 healthy controls, 327 HBV-clearance subjects, and 3976 HBV-positive subjects including 1495 HCC patients, using quantitative PCR. HBV mutations were determined by sequencing. The NFKBIA promoter activity was assessed by transient transfection. Multiplicative interactions of the polymorphisms and viral mutations were assessed by multivariate logistic regression.

RESULTS

Compared with HBV-clearance subjects, rs2233406 (CT versus CC) and rs3138053 (AG or AG + GG versus AA) significantly decreased HBV persistence, especially in the genotype B HBV-infected subjects. In the genotype C HBV-infected subjects, rs2233406 variant genotypes were significantly associated with an increased risk of HCC [CT versus CC: age-, gender-adjusted odds ratio (AOR), 1.33; 95% confidence interval (CI) 1.01-1.75 in training set and AOR, 1.59; 95% CI 1.01-2.52 in validation set] compared with HCC-free HBV-infected subjects and significantly increased the frequencies of HCC-related HBV mutations (A1762T/G1764A, T1753V, preS1 start codon mutation, and preS deletion); rs28362491 (Del/Del or Ins/Del + Del/Del versus Ins/Ins) significantly increased the frequency of A1762T/G1764A and reduced the frequency of preS2 start codon mutation. The variant genotypes impaired NFKBIA promoter activity in hepatic cells. The interaction of rs2233406 variant genotypes (CT + TT versus CC) with A1762T/G1764A significantly increased HCC risk in genotype C HBV-infected subjects, with AOR of 2.61 (95% CI 1.09-6.26).

CONCLUSION

Genetic polymorphisms improving NF-κB activity contribute to genotype B HBV clearance. The rs2233406 variant genotypes significantly increase HCC risk, possibly via facilitating immune selection of the HBV mutations. The host-virus interactions are important in identifying HBV-infected subjects who are more likely to develop HCC.

Screening for characteristic genes in osteoarthritis induced by destabilization of the medial meniscus utilizing bioinformatics approach

OBJECTIVE

To explore the underlying molecular mechanism of the development of OA (osteoarthritis).

METHODS

The expression profile dataset GSE26475 was downloaded from Gene Expression Omnibus database. A total of 21 samples were available, including knee joint samples from OA mice induced by DMM (Destabilization of the medial meniscus) surgery (6h, 3d, 7d), mice undergoing sham (only capsulotomy) surgery (6h, 3d, 7d) and the age matched Naïve mice (normal controls) that were not operated on. The differentially expressed genes (DEGs) were identified and the KEGG pathway enrichment analysis was conducted for all DEGs.

RESULTS

The number of DEGs between the DMM-induced mice at different times after surgery and normal controls was different that it decreased from 6h to 3d while increased at 7d. The same was true for the change of the number of DEGs between DMM and sham groups. Further analysis revealed that the DEGs between DMM and normal controls were mainly involved in the signaling and inflammation related pathways. Total 16 DEGs between DMM and sham groups at 7d were all involved in the Parkinson's disease, Oxidative phosphorylation and Alzheimer's disease pathways.

CONCLUSION

The results presented here may help us to understand the molecular mechanism of OA.