灌木铁线莲繁育系统特征及其花下垂现象的适应性意义

该研究对兰州市北山地区自然居群下的灌木铁线莲(Clematis fruticosa Turcz.)的繁育系统特征进行了实验分析,并通过对其花朵进行人工上举处理,研究了花朝向改变(花朵上举)后访花昆虫、花粉数量和质量变化以及结籽率和种子特征的变化,以此反证花朵下垂的适应性意义。结果表明:(1)自然状态下,灌木铁线莲的P/O值为9579.5,属于专性异花授粉;套袋实验结果显示,灌木铁线莲自交亲和,兼具异交和自交的混合交配系统,但不存在无融合生殖现象。(2)灌木铁线莲的主要传粉者为东亚无垫蜂(Amegill aparhypate)和中华蜜蜂(Apis cerana);人工上举处理改变花朝向后,两种传粉昆虫的访花频率和单花停留时间与自然条件下没有发生变化,但因雨水冲刷造成其花粉数量显著下降,且阳光直射使花粉活力显著下降,说明花朝向改变会降低其雄性适合度。(3)花朝向改变后,灌木铁线莲结籽率显著下降,种子宿存花柱长度降低,但并没有影响种子大小和千粒重,说明花朝向改变降低了雌性适合度,并影响到灌木铁线莲种子传播。研究结果证实,灌木铁线莲花期花朵下垂现象对有效传粉昆虫影响不大,但可以显著提高植物雄性适合度和雌性适合度,并作为一种有效的适应策略保障了其繁殖成功。     

Pectolinarigenin prevents bone loss in ovariectomized mice and inhibits RANKL-induced osteoclastogenesis via blocking activation of MAPK and NFATc1 signaling

Osteoporosis (OP) is a metabolic disease caused by multiple factors, which is characterized by a reduction of bone mass per unit volume and destruction of bone microstructure. Aberrant osteoclast function is the main cause of OP, therefore, regulating the differentiation and function of osteoclast is one of the treatment strategies for OP. Pectolinarigenin (PEC) is a medicinal implant isolated from Fragrant Eupatorium. Our experimental data showed that PEC was able to inhibit receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis in vitro, by tartrate-resistant acid phosphatase (TRAcP) staining, Fibrous actin ring formation, and hydroxyapatite resorption assays. In terms of mechanism, PEC inhibited the expression of the osteoclastogenesis-related gene, including cathepsin K (Ctsk), matrix metalloproteinase 9 (Mmp9), and TRAcP (Acp5). Western blot analysis demonstrated that PEC could significantly block the activation of RANKL-induced mitogen-activated protein kinase signaling cascades and was able to suppress the protein expression of nuclear factor of activated T-cells and c-Fos. Meanwhile, the intracellular reactive oxygen species levels were also reduced by PEC in a concentration-dependent manner. Further, PEC could prevent the ovariectomy-induced bone loss in vivo. Summarizing all, our data suggested that PEC inhibits osteoclast formation and function and RANKL signaling pathways, and thus could potentially be used in the treatment the osteoclast-related bone loss diseases.     

Diverse viromes in polar regions: A retrospective study of metagenomic data from Antarctic animal feces and Arctic frozen soil in 2012–2014

Antarctica and the Arctic are the coldest places, containing a high diversity of microorganisms, including viruses, which are important components of polar ecosystems. However, owing to the difficulties in obtaining access to animal and environmental samples, the current knowledge of viromes in polar regions is still limited. To better understand polar viromes, this study performed a retrospective analysis using metagenomic sequencing data of animal feces from Antarctica and frozen soil from the Arctic collected during 2012–2014. The results reveal diverse communities of DNA and RNA viruses from at least 23 families from Antarctic animal feces and 16 families from Arctic soils. Although the viral communities from Antarctica and the Arctic show a large diversity, they have genetic similarities with known viruses from different ecosystems and organisms with similar viral proteins. Phylogenetic analysis of Microviridae, Parvoviridae, and Larvidaviridae was further performed, and complete genomic sequences of two novel circular replication-associated protein (rep)-encoding single-stranded (CRESS) DNA viruses closely related to Circoviridae were identified. These results reveal the high diversity, complexity, and novelty of viral communities from polar regions, and suggested the genetic similarity and functional correlations of viromes between the Antarctica and Arctic. Variations in viral families in Arctic soils, Arctic freshwater, and Antarctic soils are discussed. These findings improve our understanding of polar viromes and suggest the importance of performing follow-up in-depth investigations of animal and environmental samples from Antarctica and the Arctic, which would reveal the substantial role of these viruses in the global viral community.     

Discovery of novel EGFR tyrosine kinase inhibitors by structure-based virtual screening

By using of structure-based virtual screening, 13 novel epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors were discovered from 197,116 compounds in the SPECS database here. Among them, 8 compounds significantly inhibited EGFR kinase activity with IC(50) values lower than 10 μM. 3-{[1-(3-Chloro-4-fluorophenyl)-3,5-dioxo-4-pyrazolidinylidene]methyl}phenyl 2-thiophenecarboxylate (13), particularly, was the most potent inhibitor possessing the IC(50) value of 3.5 μM. The docking studies also provide some useful information that the docking models of the 13 compounds are beneficial to find a new path for designing novel EGFR inhibitors.     

A locus for autosomal dominant accessory auricular anomaly maps to 14q11.2–q12

Accessory auricular anomaly is a small excrescence of skin that contains elastic cartilage on different regions of the helix and the face. Previous work has shown that the genetic trait of some patients with the isolated symptom of accessory auricular anomaly is autosomal dominant. To map the gene for autosomal dominant accessory auricular anomaly (ADAAA), we investigated a Chinese family with 11 affected individuals. We performed linkage analysis with microsatellite markers spanning the whole human-genome in the family. The inheritance pattern of the ADAAA family was autosomal dominant with complete penetrance. Two-point linkage analysis revealed significant maximum LOD scores of 4.20(D14S990 and D14S264, sita = 0) in the family. Haplotype construction and multipoint linkage analysis also confirmed the locus and defined the isolated ADAAA locus to a 9.84 cM interval between the markers D14S283 and D14S297. Our study assigned an isolated ADAAA locus to 14q11.2–q12. This is the first ADAAA locus reported to date.Y. Yang and J. Guo contribute to this work equally.     

Permeabilization of <Emphasis Type="Italic">Microbacterium oxylans</Emphasis> shifts the conversion of puerarin from puerarin-7-<Emphasis Type="Italic">O</Emphasis>-glucoside to puerarin-7-<Emphasis Type="Italic">O</Emphasis>-fructoside

The main product of the conversion of puerarin by unpermeabilized cells of bacterium Microbacterium oxydans CGMCC 1788 was puerarin-7-O-glucoside (241 ± 31.9 μM). Permeabilization with 40% ethanol could not increase conversion yield, whereas it resulted in change of main product; a previous trace product became a main product (213 ± 48.0 μM) which was identified as a novel puerarin-7-O-fructoside by electrospray ionization time-of-flight MS, ¹³C NMR, ¹H NMR, and GC-MS analysis of sugar composition, and puerarin-7-O-glucoside became a trace product (14.8 ± 5.4 μM). However, the extract from cells of M. oxydans CGMCC 1788 permeabilized with ethanol converted puerarin to form 113.9 ± 27.7 μM puerarin-7-O-glucoside and 187.8 ± 29.5 μM puerarin-7-O-fructoside under the same conditions. When unpermeabilized intact cells were recovered and used repeatedly for the conversion of puerarin, with increase of reuse times, the yield of puerarin-7-O-glucoside gradually decreased, whereas the yield of puerarin-7-O-fructoside increased gradually in the conversion mixture. The main product of the conversion of puerarin by the tenth recycled unpremerbilized cells was puerarin-7-O-fructoside (288.4 ± 24.0 μM). Therefore, the change of permeability of cell membrane of bacterium M. oxydans CGMCC 1788 contributed to the change of conversion of the product’s composition.     

Integrated analysis identifies RAC3 as an immune-related prognostic biomarker associated with chemotherapy sensitivity in endometrial cancer

Endometrial cancer (EC) is one of the most common gynaecological malignant tumours with a high incidence, leading to urgent demands for exploring novel carcinogenic mechanisms and developing rational therapeutic strategies. The rac family of small GTPase 3 (RAC3) functions as an oncogene in various human malignant tumours and plays an important role in tumour development. However, the critical roles of RAC3 in the progression of EC need further investigation. Based on TCGA, single-cell RNA-Seq, CCLE and clinical specimens, we revealed that the RAC3 was specifically distributed in EC tumour cells compared to normal tissues and functioned as an independent diagnostic marker with a high area under curve (AUC) score. Meanwhile, the RAC3 expression in EC tissues was also correlated with a poor prognosis. In detail, the high levels of RAC3 in EC tissues were reversely associated with CD8⁺T cell infiltration and orchestrated an immunosuppressive microenvironment. Furthermore, RAC3 accelerated tumour cell proliferation and inhibited its apoptosis, without impacting cell cycle stages. Importantly, silencing RAC3 improved the sensitivity of EC cells to chemotherapeutic drugs. In this paper, we revealed that RAC3 was predominantly expressed in EC and significantly correlated with the progression of EC via inducing immunosuppression and regulating tumour cell viability, providing a novel diagnostic biomarker and a promising strategy for sensitizing chemotherapy to EC.