Phytochemical library screening reveals betulinic acid as a novel Skp2-SCF E3 ligase inhibitor in non-small cell lung cancer.

Skp2 is overexpressed in multiple cancers and plays a critical role in tumor development through ubiquitin/proteasome-dependent degradation of its substrate proteins. Drugs targeting Skp2 have exhibited promising anticancer activity. Here, we identified a plant-derived Skp2 inhibitor, betulinic acid (BA), via high-throughput structure-based virtual screening of a phytochemical library. BA significantly inhibited the proliferation and migration of non-small cell lung cancer (NSCLC) through targeting Skp2-SCF E3 ligase both in vitro and in vivo. Mechanistically, BA binding to Skp2, especially forming H-bonds with residue Lys145, decreases its stability by disrupting Skp1-Skp2 interactions, thereby inhibiting the Skp2-SCF E3 ligase and promoting the accumulation of its substrates; that is, E-cadherin and p27. In both subcutaneous and orthotopic xenografts, BA significantly inhibited the proliferation and metastasis of NSCLC through targeting Skp2-SCF E3 ligase and upregulating p27 and E-cadherin protein levels. Taken together, BA can be considered a valuable therapeutic candidate to inhibit metastasis of NSCLC.

LncRNA AFAP1-AS1 promotes osteoblast differentiation of human aortic valve interstitial cells through regulating miR-155/SMAD5 axis.

AIM: Degenerative calcific aortic valve disease (DCAVD) is a common valve disease characterized by massive calcium deposits in the aortic valve. Osteoblast differentiation of valve interstitial cells (VICs) is responsible for the formation of calcific nodules. This study aims to explore the function and underlying mechanism of long non-coding RNA (lncRNA) AFAP1-AS1 (actin filament-associated protein 1 antisense RNA 1) in the pathogenesis of DCAVD. METHODS: AFAP1-AS1, miR-155 and mRNA levels were detected by qRT-PCR. Protein levels were measured by Western blot. Calcification deposition was examined by Alizarin Red staining. The interaction between AFAP1-AS1 and miR-155, as well as miR-155 and SMAD5 was evaluated using luciferase reporter assay. RESULTS: AFAP1-AS1 expression was increased both in calcified aortic valves from DCAVD patients and after osteogenic induction in human VICs. Furthermore, AFAP1-AS1 overexpression promoted osteogenic differentiation of VICs, whereas AFAP1-AS1 knockdown inhibited osteogenic differentiation. Mechanistically, AFAP1-AS1 acted as a sponge for miR-155 to elevate SMAD5 expression. Further functional assays revealed that miR-155 mimic and SMAD5 silencing effectively reversed AFAP1-AS1-promoted osteogenic differentiation of VICs. CONCLUSION: Collectively, AFAP1-AS1 promotes osteogenic differentiation of VICs, at least in part, by sponging miR-155 to upregulate SMAD5. This study sheds new light on lncRNA-directed therapeutics in DCAVD.

Perceptions of Chinese Biomedical Researchers Towards Academic Misconduct: A Comparison Between 2015 and 2010.

Publications by Chinese researchers in scientific journals have dramatically increased over the past decade; however, academic misconduct also becomes more prevalent in the country. The aim of this prospective study was to understand the perceptions of Chinese biomedical researchers towards academic misconduct and the trend from 2010 to 2015. A questionnaire comprising 10 questions was designed and then validated by ten biomedical researchers in China. In the years 2010 and 2015, respectively, the questionnaire was sent as a survey to biomedical researchers at teaching hospitals, universities, and medical institutes in mainland China. Data were analyzed by the Chi squared test, one-way analysis of variance with the Tukey post hoc test, or Spearman's rank correlation method, where appropriate. The overall response rates in 2010 and 2015 were 4.5% (446/9986) and 5.5% (832/15,127), respectively. Data from 15 participants in 2010 were invalid, and analysis was thus performed for 1263 participants. Among the participants, 54.7% thought that academic misconduct was serious-to-extremely serious, and 71.2% believed that the Chinese authorities paid no or little attention to the academic misconduct. Moreover, 70.2 and 65.2% of participants considered that the punishment for academic misconduct at the authority and institution levels, respectively, was not appropriate or severe enough. Inappropriate authorship and plagiarism were the most common forms of academic misconduct. The most important factor underlying academic misconduct was the academic assessment system, as judged by 50.7% of the participants. Participants estimated that 40.1% (39.8 ± 23.5% in 2010; 40.2 ± 24.5% in 2015) of published scientific articles were associated with some form of academic misconduct. Their perceptions towards academic misconduct had not significantly changed over the 5 years. Reform of the academic assessment system should be the fundamental approach to tackling this problem in China.

Efficient Generation of Gene-Modified Pigs Harboring Precise Orthologous Human Mutation via CRISPR/Cas9-Induced Homology-Directed Repair in Zygotes.

Precise genetic mutation of model animals is highly valuable for functional investigation of human mutations. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9)-induced homology-directed repair (HDR) is usually used for precise genetic mutation, being limited by the relatively low efficiency compared with that of non-homologous end joining (NHEJ). Although inhibition of NHEJ was shown to enhance HDR-derived mutation, in this work, without inhibition of NHEJ, we first generated gene-modified pigs harboring precise orthologous human mutation (Sox10 c.A325>T) via CRISPR/Cas9-induced HDR in zygotes using single-strand oligo DNA (ssODN) as template with an efficiency as high as 80%, indicating that pig zygotes exhibited high activities of HDR relative to NHEJ and were highly amendable to genetic mutation via CIRSPR/Cas9-induced HDR. Besides, we found a higher concentration of ssODN remarkably reduced HDR-derived mutation in pig zygotes, suggesting a possible balance for optimal HDR-derived mutation in zygotes between the excessive accessibility to HDR templates and the activities of HDR relative to NHEJ which appeared to be negatively correlated to ssODN concentration. In addition, the HDR-derived mutation, as well as those from NHEJ, extensively integrated into various tissues including gonad of founder pig without detected off-targeting, suggesting CRISPR/Cas9-induced HDR in zygotes is a reliable approach for precise genetic mutation in pigs.

A novel gemycircularvirus in an unexplained case of child encephalitis.

BACKGROUND: Recently, a diverse group of viruses with circular, replication initiator protein(Rep) encoding, single stranded DNA (CRESS-DNA) genomes, were discovered from wide range of eukaryotic organisms ranging from mammals to fungi. Gemycircularvirus belongs to a distinct group of CRESS-DNA genomes and is classified under the genus name of Gemycircularvirus. FINDINGS: Here, a novel gemycircularvirus named GeTz1 from cerebrospinal fluid sample of a child with unexplainable encephalitis was characterized. The novel gemycircularvirus encodes two major proteins, including a capsid protein (Cap) and a replication-associated protein (Rep). Phylogenetic analysis based on the amino acid sequence of Rep indicated that GeTz1 clusters with one gemycircularvirus discovered from bird (KF371633), sharing 46.6 % amino acid sequence identity with each other. CONCLUSION: A novel gemycircularvirus was discovered from cerebrospinal fluid sample of a child with unexplainable encephalitis. Further studies, such as testing human sera for specific antibodies, should be performed to investigate whether gemycircularvirus infects human and is associated with encephalitis.

Polyanion binding accelerates the formation of stable and low-toxic aggregates of ALS-linked SOD1 mutant A4V.

The toxic property thus far shared by both ALS-linked SOD1 variants and wild-type SOD1 is an increased propensity to aggregation. However, whether SOD1 oligomers or aggregates are toxic to cells remains to be well defined. Moreover, how the toxic SOD1 species are removed from intra- and extracellular environments also needs to be further explored. The DNA binding has been shown to be capable of accelerating the aggregatio\n of wild-type and oxidized SOD1 forms under acidic and neutral conditions. In this study, we explore the binding of DNA and heparin, two types of essential life polyanions, to A4V, an ALS-linked SOD1 mutant, under acidic conditions, and its consequences. The polyanion binding alters the A4V conformation, neutralizes its local positive charges, and increases its local concentrations along the polyanion chain, which are sufficient to lead to acceleration of the pH-dependent A4V aggregation. The accelerated aggregation, which is ascribed to the polyanion binding-mediated removal or shortening of the lag phase in aggregation, contributes to the formation of amorphous A4V nanoparticles. The prolonged incubation with polyanions not only results in the complete conversion of likely soluble toxic A4V oligomers into non- and low-toxic SDS-resistant aggregates, but also increases their stability. Although this is only an initial step toward reducing the toxicity of SOD1 mutants, the accelerating role of polyanions in protein aggregation might become one of the rapid pathways that remove toxic forms of SOD1 mutants from intra- and extracellular environments.

Determination of free fatty acids in edible oil based on hollow mesoporous silica nanoparticles.

In our study, ammoniated hollow mesoporous silica nanoparticles (NH2-HMSN) with uniform diameter and stable structure were successively prepared via SiO2 core hard template method. Fourier transformed infrared spectroscopy revealed that amino group was effectively modified. Adsorption experiments showed that adsorption capacity of NH2-HMSN towards free fatty acids (FFAs) was superior to aminated mesopores or silica microspheres. Following through optimization of extraction conditions, FFAs from edible oil samples were successfully gathered by NH2-HMSN and showed favorable linearities (0.2-90 µg g-1), remarkably low limit of detections (0.03-0.15 nmol g-1), acceptable recoveries (85.08-96.82 %) and relatively accurate precisions (1.64-4.99 %). In comparison to existing adsorbent, NH2-HMSN could be successfully prepared via the chemical reaction of common raw materials under normal pressure and temperature. Furthermore, NH2-HMSN with hollow and mesoporous structure was more effective than the current adsorbents aimed at FFAs analysis in aspect of surface area and adsorption capacity.

Centipeda minima extract sensitizes lung cancer cells to DNA-crosslinking agents via targeting Fanconi anemia pathway.

BACKGROUND: Intrinsic and acquired chemoresistance remains a critical challenge in lung cancer chemotherapy. Fanconi anemia (FA) pathway plays an important role in antagonizing the cytotoxic effects of chemotherapeutics by repairing DNA damage. We recently demonstrated that the traditional Chinese medicinal herb, Centipeda minima (C. minima), possessed anti-inflammatory and antioxidant properties. However, the potential anticancer application of C. minima and the underlying mechanisms remain unclear. PURPOSE: We aimed to investigate the combined anticancer effects of the ethanol extract of C. minima (ECM) and DNA-crosslinking agents on non-small cell lung cancer (NSCLC) and elucidate the underlying mechanisms. METHODS: Cell viability and flow cytometry assay were performed to determine the synergistic cytotoxicity of ECM and DNA-crosslinking agents, cisplatin (CDDP) or mitomycin C (MMC), in NSCLC cells. Western blotting and immunofluorescence were conducted to examine the effects of ECM on protein expression in DNA damage repair pathway. Comet assay was applied to evaluate DNA damage levels. Subcutaneous xenografts of NSCLC were established to evaluate the combined anticancer effects of ECM and CDDP. RESULTS: Combined treatments with ECM and DNA-crosslinking agents exhibited synergistic cytotoxic effects against A549 and H1299 cells. FANCD2 was highly expressed in NSCLC that correlates with poor prognosis of NSCLC patients, based on the online database analysis. ECM significantly inhibited DNA damage-induced monoubiquitination and nuclear foci formation of FANCD2, thereby sensitizing NSCLC to CDDP- or MMC-induced DNA damage and apoptosis, as evidenced by increased expression of γ-H2AX, increased cleavage of caspases-3 and PARP, and enhanced Annexin V-FITC/PI staining. Further, ECM can also decrease the protein level of FANCD2 that contributes to the chemosensitizing effects. Moreover, ECM significantly attenuated CDDP-mediated S-phase arrest by antagonizing the activation of ATR/Chk1 pathway in NSCLC cells. Animal experiments further demonstrated that ECM and CDDP combination treatment synergistically inhibited tumor growth by decreasing FANCD2 protein level in tumor tissues. CONCLUSION: Our results demonstrated that ECM can inhibit DNA-crosslinking agents-induced activation of FA pathway by attenuating both the expression and monoubiquitination of FANCD2. ECM and CDDP combination therapy exhibited synergistic anticancer effects both in vitro and in vivo, indicating that ECM and its active components might serve as novel anticancer drugs in the combination chemotherapy.

Identification of pseudolaric acid B as a novel Hedgehog pathway inhibitor in medulloblastoma.

Aberrant activation of the Hedgehog (Hh) pathway is implicated in the pathogenesis and development of multiple cancers, especially Hh-driven medulloblastoma (MB). Smoothened (SMO) is a promising therapeutic target of the Hh pathway in clinical cancer treatment. However, SMO mutations frequently occur, which leads to drug resistance and tumor relapse. Novel inhibitors that target both the wild-type and mutant SMO are in high demand. In this study, we identified a novel Hh pathway inhibitor, pseudolaric acid B (PAB), which significantly inhibited the expression of Gli1 and its transcriptional target genes, such as cyclin D1 and N-myc, thus inhibiting the proliferation of DAOY and Ptch1+/- primary MB cells. Mechanistically, PAB can potentially bind to the extracellular entrance of the heptahelical transmembrane domain (TMD) of SMO, based on molecular docking and the BODIPY-cyclopamine binding assay. Further, PAB also efficiently blocked ciliogenesis, demonstrating the inhibitory effects of PAB on the Hh pathway at multiple levels. Thus, PAB may overcome drug-resistance induced by SMO mutations, which frequently occurs in clinical setting. PAB markedly suppressed tumor growth in the subcutaneous allografts of Ptch1+/- MB cells. Together, our results identified PAB as a potent Hh pathway inhibitor to treat Hh-dependent MB, especially cases resistant to SMO antagonists.

Realization of wafer-scale nanogratings with sub-50 nm period through vacancy epitaxy.

Gratings, one of the most important energy dispersive devices, are the fundamental building blocks for the majority of optical and optoelectronic systems. The grating period is the key parameter that limits the dispersion and resolution of the system. With the rapid development of large X-ray science facilities, gratings with periodicities below 50 nm are in urgent need for the development of ultrahigh-resolution X-ray spectroscopy. However, the wafer-scale fabrication of nanogratings through conventional patterning methods is difficult. Herein, we report a maskless and high-throughput method to generate wafer-scale, multilayer gratings with period in the sub-50 nm range. They are fabricated by a vacancy epitaxy process and coated with X-ray multilayers, which demonstrate extremely large angular dispersion at approximately 90 eV and 270 eV. The developed new method has great potential to produce ultrahigh line density multilayer gratings that can pave the way to cutting edge high-resolution spectroscopy and other X-ray applications.

[Pollution Characteristics, Source Analysis and Potential Ecological Risk Assessment of Heavy Metals in Soils Surrounding a Municipal Solid Waste Incineration Plant in Shanghai].

The contents of ten heavy metals (As, Cu, Cd, Cr, Pb, Ni, Zn, Ti, Mn, and Hg) were determined in the surface soils surrounding a municipal solid waste incineration plant in Shanghai using atomic spectroscopy. The spatial distribution and sources of the detected heavy metals were studied by enrichment factor and multivariate statistical and spatial interpolation analyses. In addition, their potential ecological risk was assessed. The results showed that all heavy metals, except Hg and As, were detected with mean contents ranging from 0.399 to 4220 mg·kg-1. The mean contents of Cu, Cd, Cr, Pb, Ni, Zn, and Mn were higher than their respective background values in Shanghai. In particular, the mean content of Cd was 2.9 times its background value. The results of the Pearson's correlation, principle component, enrichment factor, and spatial distribution analyses of these heavy metals indicated that Ti, Mn, and Ni primarily originated from natural sources, while Cd, Cr, Cu, Pb, and Zn originated from industrial manufacturing, combustion, and traffic emissions. The potential ecological risk assessment showed that soils surrounding the municipal solid waste incineration plant suffered from a moderate-level risk. The mean value of the potential ecological risk index of these detected heavy metals was 108.92, of which Cd contributed as high as 79.63%, deserving much attention.

[Clinical evaluation of the heart function early after repair of tetralogy of Fallot: follow-up of 43 patients].

OBJECTIVE: To evaluate the heart function of the patients early after the repair of tetralogy of Fallot (TOF). METHODS: Forty-three patients with TOF, 25 males and 18 females, underwent operation at the age of 2.5 - 52 years (16.7 years on average) and were followed up for 1 - 3.5 years. Twenty-one age-matched healthy persons were used as controls. Tissue Doppler imaging (TDI) was used to measure the values of the peak tricuspid ring velocity during early diastole (Ea), late diastole (Aa), systole, and isovolumic contraction, and isovolumetric contraction acceleration (IVA); and isovolumetric contraction time (ICT), isovolumetric relaxation time (IRT), and isovolumetric contraction velocity (IVV) of the right ventricle. Tei index was calculated using the formula: (ICT + IRT)/ET. Treadmill test was used on the patients aged > 17 to measure the maximal heart rate maximal blood pressure, maximal exercise tolerance (MET), and movement time. RESULTS: The peak tricuspid ring velocity during Ea of the repaired TOF group (rTOF group) was 11.5 +/- 2.6 cm/s, significantly lower than that of the control group (17.1 +/- 2.4 cm/s, P < 0.0001), the peak tricuspid ring velocity during Aa of the rTOF group was 9.6 +/- 1.7 cm/s, significantly lower than that of the control group (12.9 +/- 2.9 cm/s, P < 0.001), the E/A of the rTOF group was 1.16 +/- 0.36, significantly lower than that of the control group (1.36 +/- 0.26, P < 0.05). The IVV of the rTOF group was 7.7 +/- 1.8 cm/s, significantly lower than that of the control group (9.9 +/- 1.4 cm/s, P = 0.0030, and the IVA of the rTOF group was 131.7 +/- 37.6 cm/s(2), significantly lower than that of the control group (222.5 +/- 39.2 cm/s(2), P < 0.001). The Tei index of the rTOF group was 0.58 +/- 0.11, significantly higher than that of the control group (0.52 +/- 0.04, P = 0.029). The maximal heart rate maximal blood pressure, MET, and movement time of the rTOF group were all significantly lower than those of the control group (P < 0.05 or P < 0.01). CONCLUSION: The heart function of the patients undergoing repair of TOF fails to recover to the normal level during a short time after the surgery.

Influence of Chitosan Nanoparticles as the Absorption Enhancers on Salvianolic acid B In vitro and In vivo Evaluation.

BACKGROUND: Salvianolic acid B (SalB) represents the most abundant and bio-active phenolic constituent among the water-soluble compounds of Salvia miltiorrhiza. But the therapeutic potential of SalB has been significantly restricted by its poor absorption. METHODS: In this study, chitosans (CS) and CS nanoparticles (NPs) with different molecular weights (MWs), which have influence on the absorption of SalB, was also investigated. RESULTS: As a preliminary study, water-soluble CS with various MWs (3, 30, 50, and 100 kDa) was chosen. We investigated the MW-dependent Caco-2 cell layer transport phenomena in vitro of CS and NPs at concentrations (4 µg/ml, w/v). SalB, in presence CS or NPs has no significant toxic effect on Caco-2 cell. As the MW increases, the absorption enhancing effect of CS increases. However, as the MW decreases, the absorption enhancing effect of NPs increases. The AUC0-∞ of the SalB-100 kDa CS was 4.25 times greater than that of free SalB. And the AUC0-∞ of the SalB-3 kDa NPs was 16.03 times greater than that of free SalB. CONCLUSION: CS and NPs with different MWs as the absorption enhancers can promote the absorption of SalB. And the effect on NPs is better than CS. SUMMARY: Formation mechanism for NPs.

The effect of a nuclear localization sequence on transfection efficacy of genes delivered by cobalt(II)-polybenzimidazole complexes.

We have demonstrated that the metal complexes of polybenzimidazoles are emerging likely as a new type of gene-delivery systems based on their strong DNA-condensing ability. However, the in vitro transfection efficacy of the DNA condensates formed with the metal complexes was relatively low. The positively charged peptides, such as cell-penetrating peptides and nuclear localization sequences (NLSs), have been reported to be capable of enhancing expression of the transgenes, likely as they promote entrance of their electrostatic complexes with DNA into the nuclear through nuclear pores. Here, we explored expression of the genes transferred by a series of Co(II) complexes in the presence of NLS (PKKKRKV) in normal and cancer cell lines. The results showed that the Co(II) complexes lead to the more pronounced DNA condensation in the presence of NLS than that in the absence of NLS. The binding of NLS prior to addition of the Co complexes can significantly reduce both the size and the population of the condensates at the given Co complexes/DNA ratios, compared with the NLS-free condensates. Meanwhile, the binding of NLS can considerably increase surface positive charges on the DNA nanoparticles. The suitable sizes and high surface positive charges facilitate the entrance of the nanoparticles into cells. Luciferase activity assay indicated that the transfection efficacy of the NLS-bound condensates was five-fold of that of the NLS-free ones in different cell lines, and comparable to that of the condensate formed with the commercially available carrier PEI. Moreover, cell viability assay of the NLS-bound condensates showed lower cytotoxicity than the NLS-free ones. Thus, the combination of NLS and cationic metal complexes might offer a new type of ternary delivery systems.

The chelation targeting metal-Aß40 aggregates may lead to formation of Aß40 oligomers.

The fluorescent chelator (FC-1) was designed by combining a metal-chelating unit and a ThT-based Aß aggregate-binding fluorescent unit. FC-1 is a cell membrane-penetrable chelator with a moderate chelation ability to Cu(2+) and Zn(2+) and can target metal-Aß40 aggregates. Treatment with FC-1 led to enhanced cytotoxicity of the aggregates, because the aggregates were converted into a pool of oligomers.

Right ventricular dysfunction due to right ventricular outflow tract patch.

Doppler tissue imaging analysis was used to examine the relationship between right ventricular function and right ventricular outflow tract damage in 54 patients with repaired tetralogy of Fallot. The patients were divided into three groups: 16 in whom the right ventricular outflow tract was directly sutured (group DS), 23 who had transventricular patch repair (group TVP), and 15 who had transannular patch repair (group TAP). The control group consisted of 16 age-matched patients who underwent patch closure of a ventricular septal defect (group C). The Tei index was obtained from tricuspid and pulmonary Doppler flow velocities. The right ventricular Tei index was significantly greater in groups TVP and TAP than in group DS. Doppler tissue imaging analysis in groups TVP and TAP showed shorter myocardial systolic velocity, diastolic peak velocity, and atrial diastolic peak velocity, lower peak myocardial velocity and acceleration during isovolumic contraction, and prolonged isovolumic relaxation and contraction times compared to groups DS and C. Right ventricular dysfunction is due to the right ventricular outflow tract patch. Thus, the right ventricular outflow tract may be essential for right ventricular ejection and maintenance of right ventricular function.