Femtosecond X-ray-induced explosion of C60 at extreme intensity

Understanding molecular femtosecond dynamics under intense X-ray exposure is critical to progress in biomolecular imaging and matter under extreme conditions. Imaging viruses and proteins at an atomic spatial scale and on the time scale of atomic motion requires rigorous, quantitative understanding of dynamical effects of intense X-ray exposure. Here we present an experimental and theoretical study of C60 molecules interacting with intense X-ray pulses from a free-electron laser, revealing the influence of processes not previously reported. Our work illustrates the successful use of classical mechanics to describe all moving particles in C60, an approach that scales well to larger systems, for example, biomolecules. Comparisons of the model with experimental data on C60 ion fragmentation show excellent agreement under a variety of laser conditions. The results indicate that this modelling is applicable for X-ray interactions with any extended system, even at higher X-ray dose rates expected with future light sources.

Huge critical current density and tailored superconducting anisotropy in SmFeAsO₀.₈F₀.₁₅ by low-density columnar-defect incorporation

Iron-based superconductors could be useful for electricity distribution and superconducting magnet applications because of their relatively high critical current densities and upper critical fields. SmFeAsO₀.₈F₀.₁₅ is of particular interest as it has the highest transition temperature among these materials. Here we show that by introducing a low density of correlated nano-scale defects into this material by heavy-ion irradiation, we can increase its critical current density to up to 2 × 10⁷ A cm⁻² at 5 K--the highest ever reported for an iron-based superconductor--without reducing its critical temperature of 50 K. We also observe a notable reduction in the thermodynamic superconducting anisotropy, from 8 to 4 upon irradiation. We develop a model based on anisotropic electron scattering that predicts that the superconducting anisotropy can be tailored via correlated defects in semimetallic, fully gapped type II superconductors.

Transforming growth factor-beta 1 pathways in inflammatory airway diseases

Transforming growth factor-beta 1 (TGF-β1) has been reported being involved in the remodeling and immunosuppression processes of inflammatory airway diseases; understanding the regulation of TGF-β1 is therefore a key to unravel the pathomechanisms of these diseases. This review briefly summarizes the current knowledge on the influencing factors for driving TGF-β1 and its regulatory pathways in inflammatory airway diseases and discusses possible therapeutic approaches to TGF-β1 control. The factors include smoking and oxidative stress, prostaglandins (PGs), leukotrienes (LTs), bradykinin (BK), and microRNAs (miRs). Based on the summary, new innovative treatment strategies may be developed for inflammatory airway diseases with an impaired expression of TGF-β1.

Genome-wide identification of WRKY family genes and their response to cold stress in Vitis vinifera

BACKGROUND

WRKY transcription factors are one of the largest families of transcriptional regulators in plants. WRKY genes are not only found to play significant roles in biotic and abiotic stress response, but also regulate growth and development. Grapevine (Vitis vinifera) production is largely limited by stressful climate conditions such as cold stress and the role of WRKY genes in the survival of grapevine under these conditions remains unknown.

RESULTS

We identified a total of 59 VvWRKYs from the V. vinifera genome, belonging to four subgroups according to conserved WRKY domains and zinc-finger structure. The majority of VvWRKYs were expressed in more than one tissue among the 7 tissues examined which included young leaves, mature leaves, tendril, stem apex, root, young fruits and ripe fruits. Publicly available microarray data suggested that a subset of VvWRKYs was activated in response to diverse stresses. Quantitative real-time PCR (qRT-PCR) results demonstrated that the expression levels of 36 VvWRKYs are changed following cold exposure. Comparative analysis was performed on data from publicly available microarray experiments, previous global transcriptome analysis studies, and qRT-PCR. We identified 15 VvWRKYs in at least two of these databases which may relate to cold stress. Among them, the transcription of three genes can be induced by exogenous ABA application, suggesting that they can be involved in an ABA-dependent signaling pathway in response to cold stress.

CONCLUSIONS

We identified 59 VvWRKYs from the V. vinifera genome and 15 of them showed cold stress-induced expression patterns. These genes represented candidate genes for future functional analysis of VvWRKYs involved in the low temperature-related signal pathways in grape.

Autophagic program is regulated by miR-325

Autophagy is required for the maintenance of cardiomyocytes homeostasis. However, the abnormal autophagy could lead to the development of heart failure. Autophagy is enhanced during myocardial ischemia/reperfusion; it remains to elucidate the molecular regulation of autophagy. We report here that miR-325, ARC and E2F1 constitute an axis that regulates autophagy. Our results showed that miR-325 expression is upregulated upon anoxia/reoxygenation and ischemia/reperfusion. Cardiomyocyte-specific overexpression of the miR-325 potentiates autophagic responses and myocardial infarct sizes, whereas knockdown of miR-325 inhibited autophagy and cell death. We searched for the downstream mediator of miR-325 and identified that ARC is a target of miR-325. ARC transgenic mice could attenuate autophagy and myocardial infarction sizes upon pressure-overload-induced heart failure, whereas ARC null mice exhibited an increased autophagic accumulation in the heart. The suppression of ARC by miR-325 led to its inability to repress autophagic program. In exploring the molecular mechanism by which miR-325 expression is regulated, our results revealed that the transcription factor E2F1 contributed to promote miR-325 expression. E2F1 null mice demonstrated reduced autophagy and myocardial infarction sizes upon ischemia/reperfusion. Our present study reveals a novel autophagic regulating model that is composed of E2F1, miR-325 and ARC. Modulation of their levels may provide a new approach for tackling cardiac failure.

Abstract P4-07-19: MicroRNA miR-24 enhances tumor angiogenesis and metastasis in breast cancer

MicroRNAs (miRNA) are non-coding single-stranded RNA molecules, which are produced from endogenous transcripts of short stem-loop structures. Through binding to the 3’-untranslated region (3’UTR) of different target messenger RNAs (mRNAs), microRNAs can repress the translation of the target mRNAs. Recent studies have shown that miR-24 can inhibit apoptosis of cancer cells and cardiomyocytes, and can accelerate cell proliferation. Up-regulation of miR-24 has been observed in oral carcinoma and is one of the most abundant miRNAs in cervical cancer. However, the role of miR-24 in breast cancer cell angiogenesis and metastasis is not clear.

We analyzed microRNA miR-24 levels in patients with breast carcinoma and found that miR-24 was higher in breast carcinoma samples than in breast benign tissues. We generated constructs expressing miR-24 and studied its functions using both in vitro and in vivo techniques. We found that the ectopic expression of miR-24 promoted breast cancer angiogenesis and metastasis.

Cell migration assays indicated that expression of miR-24 promoted migration of MT-1 cells and 4T1 cells. We examined proliferation of MT-1 cells and 4T1 cells transfected with miR-24 or the control vector. The experiments showed that the miR-24 transfected cells had high rates of proliferation than the vector-transfected cells. In vivo experiments indicated that the expression of miR-24 enhanced tumor growth, metastasis to lung tissues, and decreased overall mouse survival. Tumor sections were also probed with anti-CD34 antibody to examine angiogenesis. We found that miR-24 expression increased tumor-associated vascularization. We further performed tumor metastatic assays. DNA was isolated from lung tissues and subjected to PCR to indicate metastasis of the cancer cells. Typical metastatic lesions in the lungs are shown.

In the miR-24 expressing cells and tumors, expression of the phosphatases PTPN9 and PTPRF were repressed. We confirmed that miR-24 could directly target both PTPN9 and PTPRF. Consistent with this, we found that the levels of PTPN9 and PTPRF were lower in the patients with metastatic breast carcinoma. Ectopic expression of PTPN9 and PTPRF decreased cell migration, and tumor metastasis.

Our study demonstrates that miR-24 is highly expressed in human breast carcinoma. This finding suggests a role of miR-24 in breast cancer development/progression. Our results suggest that miR-24 plays a key role in breast cancer angiogenesis and metastasis. miR-24 could potentially be a target for cancer intervention.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-07-19.

ALDH1 is an independent prognostic factor for patients with stages II-III rectal cancer after receiving radiochemotherapy

Background:

About one in five patients with locally advanced rectal cancer (RC) suffers recurrence or distant metastasis after neoadjuvant therapy. We investigated how cancer stem cell markers change after neoadjuvant therapy and how these markers relate to recurrence.

Methods:

Pretreatment biopsies and postoperative specimens were taken from 64 patients with locally advanced rectal adenocarcinoma who received preoperative radiochemotherapy (RCT) between sampling. Samples were tested immunohistochemically for CD44, LGR5, ALDH1 and CD166; scores were dichotomised as high or low. The median follow-up period was 36 months.

Results:

High expression of CD44, LGR5, ALDH and CD166 was found in 38%, 5%, 48% and 10%, respectively, before RCT and 86%, 33%, 71% and 52%, respectively, after RCT. CD44 (P=0.001), LGR5 (P=0.049) and CD166 (P=0.003) were significantly upregulated after RCT. Whereas no recurrence was seen during the follow-up in the low ALDH group, 40% of the high ALDH group suffered recurrence. In multivariate COX analysis, postoperative ALDH1 independently predicted poor prognosis in patients with RC who received RCT (P=0.0095).

Conclusion:

Preoperative RCT upregulates expression of stem cell markers in patients with RC. High post-treatment ALDH1 expression predicts poor prognosis for these patients after neoadjuvant therapy.

Regulation different network analysis of rheumatoid arthritis (RA) and osteoarthritis (OA)

BACKGROUND

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic synovitis that progresses to destruction of cartilage and bone.

AIM

The purpose of this study was to employ microarray analysis combined with bioinformatics techniques to evaluate differential gene expression in BM-derived mononuclear cells obtained from patients with rheumatoid arthritis (RA) or osteoarthritis (OA) to study the pathogenesis of this disease.

MATERIALS AND METHODS

Gene expression profiles in BM-derived mononuclear cells from 9 RA and 10 OA patients were obtained from GEO.

RESULTS

The bone marrow (BM) mononuclear cells showed 2581 up-regulated and 649 down-regulated genes in RA patients relative to the OA group: Our analysis indicated that several differentially expressed genes might play crucial roles in RA development, including SP1, RARA, ETS1, ETS2, FOS and ESR1.

CONCLUSIONS

Further analysis predicted these genes might be involved in RA through cancer related pathways and immunity related pathways. Furthermore, these genes may serve as novel therapeutic targets for the treatment of RA.

Dynamics of hollow atom formation in intense x-ray pulses probed by partial covariance mapping

When exposed to ultraintense x-radiation sources such as free electron lasers (FELs) the innermost electronic shell can efficiently be emptied, creating a transient hollow atom or molecule. Understanding the femtosecond dynamics of such systems is fundamental to achieving atomic resolution in flash diffraction imaging of noncrystallized complex biological samples. We demonstrate the capacity of a correlation method called "partial covariance mapping" to probe the electron dynamics of neon atoms exposed to intense 8 fs pulses of 1062 eV photons. A complete picture of ionization processes competing in hollow atom formation and decay is visualized with unprecedented ease and the map reveals hitherto unobserved nonlinear sequences of photoionization and Auger events. The technique is particularly well suited to the high counting rate inherent in FEL experiments.

Branch Blight of Loquat Caused by Pestalotiopsis sydowiana in China

Loquat (Eriobotrya japonica) is a subtropical tree with sour and sweet fruit and its leaf derivatives are often used to treat cough and asthma with phlegm. In 2011, a severe stem and leaf disease, with 30∼60% incidence, was observed in a local loquat cultivar "Ninghaibai" in Ninghai, Zhejiang Province, China. Infected plants exhibited brown spots on the stem and leaves, which became blackish brown to grayish white with some little sporadic black acervuli (137.9 to 189.3 μm in diameter). Leaf symptoms showed large necrotic lesions (more than 20 mm) that frequently, but not exclusively, appeared along the leaf margin or dorsal surface. Necrotic spots were water-soaked, irregularly shaped, and bordered by a tan halo. Fungal isolates were obtained by placing sterilized symptomatic tissue onto acidified potato sucrose agar (PSA) medium and consistently yielded white fungal colonies that produced acervuli (385.6 to 485.4 μm in diameter) containing black, slimy spore masses at 25°C for 7 days. Conidia (20.9 to 29.8 × 7.1 to 14.5 μm) were 5-celled and spindle shaped, and basal cells of the conidia were hyaline, while the other three middle cells were heterochrome. The upper two middle cells were darker than the lower one. The apical cell typically had 2 to 3 apical appendages, was 12.0 to 33.1 μm in length, and the basal appendage was 3.3 to 7.8 μm long. Based on these morphological features, the fungus was identified as Pestalotiopsis sydowiana (2). This characterization was further confirmed by PCR amplification and sequencing of internal transcribed spacer (ITS) of the ribosomal DNA of fungus with primers ITS1: 5'-TCCGTAGGTGAACCTGCGG-3' and ITS4: 5'-TCCTCCGCTTATTGATATGC-3' (3). A representative sequence was deposited in NCBI GenBank (Accession No. JX478272). This sequence showed 99% homology with previously deposited sequences of P. sydowiana (HQ248207.1 and FJ478105.1) from Colombia and China. Pathogenicity tests were conducted by inoculating 1-year-old seedlings and detached stems from healthy field trees of cv. Ninghaibai loquat with sclertium (20 × 5 mm) or conidial suspension (10⁶ conidia ml^-1). Control seedlings were only encircled the PSA blocks or sprayed with water. Both inoculated and control plants were covered with plastic bags at about 80% relative humidity and kept in a greenhouse at 20 to 30°C for 48 h. Detached stems were incubated to prevent desiccation in a humid chamber at 100% relative humidity and 25°C for 10 days. Four days after inoculation, lesions appeared on sclertium-inoculated seedlings or detached stems, approximately 10 days earlier than those on conidial suspension-inoculated seedlings or detached stems. Symptom observed on artificially inoculated seedlings or detached stems were similar to that observed in naturally infected plants. The control plants remained healthy. P. sydowiana was reisolated from the lesions of the infected stems and leaves but not from control leaves. It had been reported that other species of Pestalotiopsis, such as P. eriobotrifolia and P. eriobotryae-japonica, can only infect leaves of loquat (1); however, to our knowledge, this is the first report that P. sydowiana cause branch blight disease on loquat in China. References: (1) G. G. Chen et al. Acta Agric. Univ. Zhejiangensis 16:153, 1990. (2) Q. X. Ge et al. Flora Fungorum Sinicorum: Pestalotiopsis, p. 185, Science Press, Beijing, 2009. (3) T. J. White, et al. PCR Protocols: A Guide to Methods and Applications, p. 315, Academic Press, San Diego, 1990.