Temporal dynamics of soil bacterial network regulate soil resistomes

Soil bacteria are diverse and form complicated ecological networks through various microbial interactions, which play important roles in soil multi-functionality. However, the seasonal effects on the bacterial network, especially the relationship between bacterial network topological features and soil resistomes remains underexplored, which impedes our ability to unveil the mechanisms of the temporal-dynamics of antibiotic resistance genes (ARGs). Here, a field investigation was conducted across four seasons at the watershed scale. We observed significant seasonal variation in bacterial networks, with lower complexity and stability in autumn, and a wider bacterial community niche in summer. Similar to bacterial communities, the co-occurrence networks among ARGs also shift with seasonal change, particularly with respect to the topological features of the node degree, which on average was higher in summer than in the other seasons. Furthermore, the nodes with higher betweenness, stress, degree, and closeness centrality in the bacterial network showed strong relationships with the 10 major classes of ARGs. These findings highlighted the changes in the topological properties of bacterial networks that could further alter antibiotic resistance in soil. Together, our results reveal the temporal dynamics of bacterial ecological networks at the watershed scale, and provide new insights into antibiotic resistance management under environmental changes.     

Pregnancy Loss Following Coxsackievirus B3 Infection in Mice during Early Gestation Due toHigh Expression of Coxsackievirus-Adenovirus Receptor (CAR) in Uterus and Embryo

Coxsackieviruses are important pathogens in children and the outcomes of neonatal infection can be serious or fatal. However, the outcomes of coxsackievirus infection during early gestation are not well defined. In this study, we examined the possibility of vertical transmission of coxsackievirus B3 (CVB3) and the effects of CVB3 infection on early pregnancy of ICR mice. We found that the coxsackievirus and adenovirus receptor (CAR) was highly expressed not only in embryos but also in the uterus of ICR mice. CVB3 replicated in the uterus 1 to 7 days post-infection (dpi), with the highest titer at 3 dpi. The pregnancy loss rate in mice infected with CVB3 during early gestation was 38.3%, compared to 4.7% and 2.7% in mock-infected and UV-inactivated-CVB3 infected pregnant mice, respectively. These data suggest that the uterus and embryo, which express abundant CAR, are important targets of CVB3 and that the vertical transmission of CVB3 during early gestation induces pregnancy loss.     

Spironolactone Attenuates Bleomycin-Induced Pulmonary Injury Partially via Modulating Mononuclear Phagocyte Phenotype Switching in Circulating and Alveolar Compartments

Background

Recent experimental studies provide evidence indicating that manipulation of the mononuclear phagocyte phenotype could be a feasible approach to alter the severity and persistence of pulmonary injury and fibrosis. Mineralocorticoid receptor (MR) has been reported as a target to regulate macrophage polarization. The present work was designed to investigate the therapeutic potential of MR antagonism in bleomycin-induced acute lung injury and fibrosis.

Methodology/Principal Findings

We first demonstrated the expression of MR in magnetic bead-purified Ly6G-/CD11b+ circulating monocytes and in alveolar macrophages harvested in bronchoalveolar lavage fluid (BALF) from C57BL/6 mice. Then, a pharmacological intervention study using spironolactone (20mg/kg/day by oral gavage) revealed that MR antagonism led to decreased inflammatory cell infiltration, cytokine production (downregulated monocyte chemoattractant protein-1, transforming growth factor β1, and interleukin-1β at mRNA and protein levels) and collagen deposition (decreased lung total hydroxyproline content and collagen positive area by Masson’ trichrome staining) in bleomycin treated (2.5mg/kg, via oropharyngeal instillation) male C57BL/6 mice. Moreover, serial flow cytometry analysis in blood, BALF and enzymatically digested lung tissue, revealed that spironolactone could partially inhibit bleomycin-induced circulating Ly6C^hi monocyte expansion, and reduce alternative activation (F4/80+CD11c+CD206+) of mononuclear phagocyte in alveoli, whereas the phenotype of interstitial macrophage (F4/80+CD11c-) remained unaffected by spironolactone during investigation.

Conclusions/Significance

The present work provides the experimental evidence that spironolactone could attenuate bleomycin-induced acute pulmonary injury and fibrosis, partially via inhibition of MR-mediated circulating monocyte and alveolar macrophage phenotype switching.     

纤维连接蛋白对支气管上皮细胞抗氧化损伤保护作用的研究

目的和方法：为验证整合素分子激活对支气管上皮细胞（BEC）的抗氧化性保护作用,本实验用臭氧（O3）攻击培养的兔BEC,测定细胞的^3H释放率、乳酸脱氢酶（LDH）释放活性及脂质过氧化产物丙二醛（MDA）含量,反映细胞损伤程度;观察纤维连接蛋白（Fn）及人工合成的精－甘－天冬氨酸片段（RGD肽）的保护效应。结果：①臭氧攻击使BEC的^3H释放率增高,Fn处理可减少臭氧所致的^3H释放,钙调素抑制剂W7能抑制Fn的这一作用,RGD可减轻臭氧所致的^3H释放;②臭氧攻击后细胞上清液中LDH释放增多,Fn或RGD处理均能降低LDH释放,W7阻断Fn的这一效奕;③臭氧作用后明显提高细胞内MDA含量,Fn或RGD可降低MDA含量;④臭氧攻击使细胞内GSH含量下降,Fn或RGD可增加BEC内GSH的含量;⑤Fn可增强BEC内过氧化氢酶（CAT）活性,但可被W7阻断,RGD则显示有剂量依赖性促进作用。结论：Fn及其特异识别片段与BEC的整合素分子结合后,可减轻臭氧对BEC细胞的损伤,其机理与经钙调素途径上调BEC抗氧化能力有关。     

Trends in the Use of Nephron-Sparing Surgery over 7 Years: An Analysis Using the R.E.N.A.L. Nephrometry Scoring System

Objective

To analyze trends in the use of partial nephrectomy, we evaluated which individual factors of renal nephrometry score (RNS) influenced the operative approach bi-annually from 2008 to 2014.

Materials and Methods

We performed a retrospective review of renal cell carcinoma treated by surgery in 2008, 2010, 2012, and 2014. The complexity of renal masses was measured using the R.E.N.A.L. nephrometry scoring system with CT or MRI. Group comparison in terms of operation year and surgical type (partial nephrectomy versus radical nephrectomy) was performed. We developed a nomogram to quantitate the likelihood of selecting partial nephrectomy over radical nephrectomy.

Results

A total of 1106 cases (237 in 2008, 225 in 2010, 292 in 2012, and 352 in 2014) were available for the study. Over the study period, the proportion of partial nephrectomies performed increased steadily from 21.5% in 2008 to 66.5% in 2014 (p < 0.05). Furthermore, use of partial nephrectomy increased steadily in all RNS complexity groups (low, moderate, and high) (p < 0.05). In the analysis of individual components of RNS, values of the R and N components increased statistically by year in the partial nephrectomy group (p < 0.05). Average AUC was 0.920.

Conclusions

The proportion of partial nephrectomies performed sharply increased over the study period. Additionally, over the study period, more partial nephrectomies were performed for renal masses of larger size and closer to the collecting system and main renal vessels. A nomogram developed based on this recent data set provides significant predictive value for surgical decision making.     

Identification,Design and Bio-Evaluation of Novel Hsp90 Inhibitors by Ligand-Based Virtual Screening

Heat shock protein 90 (Hsp90), whose inhibitors have shown promising activity in clinical trials, is an attractive anticancer target. In this work, we first explored the significant pharmacophore features needed for Hsp90 inhibitors by generating a 3D-QSAR pharmacophore model. It was then used to virtually screen the SPECS databases, identifying 17 hits. Compound S1 and S13 exhibited the most potent inhibitory activity against Hsp90, with IC₅₀ value 1.61±0.28 μM and 2.83±0.67 μM, respectively. Binding patterns analysis of the two compounds with Hsp90 revealed reasonable interaction modes. Further evaluation showed that the compounds exhibited good anti-proliferative effects against a series of cancer cell lines with high expression level of Hsp90. Meanwhile, S13 induced cell apoptosis in a dose-dependent manner in different cell lines. Based on the consideration of binding affinities, physicochemical properties and toxicities, 24 derivatives of S13 were designed, leading to the more promising compound S40, which deserves further optimization.     

Adriamycin effects on transplasma membrane redox functions in porcine neutrophils

Transplasma membrane electron transport, as assayed by external ferricyanide reduction, has been related to control of growth and hormone response of cells. Elicitor-stimulated transmembrane NADPH oxidase is important for bacteriocidal superoxide production by neutrophils. Since adriamycin is myelosuppressive and can stimulate superoxide production, its effects on the two redox systems of porcine neutrophil plasma membranes were compared. Adriamycin inhibits transplasma membrane ferricyanide and stimulates superoxide production activated by phorbol myristate acetate (PMA). Ferricyanide reduction in PMA-treated cells becomes resistant to inhibition by adriamycin. These results provide evidence for an independent effect of adriamycin on transmembrane ferricyanide reduction and on superoxide generation.     

Circular RNA circ‐RCCD promotes cardiomyocyte differentiation in mouse embryo development via recruiting YY1 to the promoter of MyD88

Congenital heart disease (CHD) is the most common birth defect, affecting approximately 1% of live births. Genetic and environmental factors are leading factors to CHD, but the mechanism of CHD pathogenesis remains unclear. Circular RNAs (circRNAs) are kinds of endogenous non‐coding RNAs (ncRNAs) involved in a variety of physiological and pathological processes, especially in heart diseases. In this study, three significant differently expressed circRNA between maternal embryonic day (E) E13 and E17 was found by microarray assay. Among them, the content of circ‐RCCD increases with the development of heart and was enriched in primary cardiomyocytes of different species, which arouses our attention. Functional experiments revealed that inhibition of circ‐RCCD dramatically suppressed the formation of beating cell clusters, the fluorescence intensity of cardiac differentiation marker MF20, and the expression of the myocardial‐specific markers CTnT, Mef2c, and GATA4. Next, we found that circ‐RCCD was involved in cardiomyocyte differentiation through negative regulation of MyD88 expression. Further experiments proved that circ‐RCCD inhibited MyD88 levels by recruiting YY1 to the promoter of MyD88; circ‐RCCD inhibited nuclear translocation of YY1. These results reported that circ‐RCCD promoted cardiomyocyte differentiation by recruiting YY1 to the promoter of MyD88. And, this study provided a potential role and molecular mechanism of circ‐RCCD as a target for the treatment of CHD.     

Functional expression of human pyruvate carboxylase for reduced lactic acid formation of Chinese hamster ovary cells (DG44)

To investigate the effect of human pyruvate carboxylase (hPC) on lactate formation in Chinese hamster ovary (CHO) cell lines, FLAG-tagged hPC was introduced into a dihydrofolate-deficient CHO cell line (DG44). Three clones expressing high levels of hPC, determined by Western blotting using an anti-FLAG monoclonal antibody, and a control cell line were established. Immunocytochemistry revealed that a substantial amount of expressed hPC protein was localized in the mitochondria of the cells. hPC expression did not impair cell proliferation. Rather, it improved cell viability at the end of adherent batch cultures with the serum-containing medium probably because of reduced lactate formation. Compared with control cells, specific lactate production rate of the three clones was decreased by 21–39%, which was because of a decreased specific glucose uptake rate and yield of lactate from glucose. Reduced lactate formation by hPC expression was also observed in suspension fed-batch cultures using a serum-free medium. Taken together, these results demonstrate that through the expression of the hPC enzyme, lactate formation in CHO cell culture can be efficiently reduced.     

Selenium-containing 15-mer peptides with high glutathione peroxidase-like activity

Glutathione peroxidase (GPX) is one of the most crucial antioxidant enzymes in a variety of organisms. Here we described a new strategy for generating a novel GPX mimic by combination of a phage-displayed random 15-mer peptide library followed by computer-aided rational design and chemical mutation. The novel GPX mimic is a homodimer consisting of a 15-mer selenopeptide with an appropriate catalytic center, a specific binding site for substrates, and high catalytic efficiency. Its steady state kinetics was also studied, and the values of k(cat)/K(m)(GSH) and k(cat)/ K(mH(2)O(2)) were found to be similar to that of native GPX and the highest among the existing GPX mimics. Moreover, the novel GPX mimic was confirmed to have a strong antioxidant ability to inhibit lipid peroxidation by measuring the content of malondialdehyde, cell viability, and lactate dehydrogenase activity. Importantly, the novel GPX mimic can penetrate into the cell membrane because of its small molecular size. These characteristics endue the novel mimic with potential perspective for pharmaceutical applications.