Platelet‐rich plasma inhibits osteoblast apoptosis and actin cytoskeleton disruption induced by gingipains through upregulating integrin β1

The aim of this study was to explore the effects of platelet‐rich plasma on gingipain‐caused changes in cell morphology and apoptosis of osteoblasts. Mouse osteoblasts MC3T3‐E1 cells were treated with gingipain extracts from Porphyromonas gingivalis in the presence or absence of platelet‐rich plasma. Apoptosis was detected with terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling staining. F‐actin was determined by phalloidin‐fluorescent staining and observed under confocal microscopy. Western blot analysis was used to detect integrin β1, F‐actin, and G‐actin protein expressions. A knocking down approach was used to determine the role of integrin β1. The platelet‐rich plasma protected osteoblasts from gingipain‐induced apoptosis in a dose‐dependent manner, accompanied by upregulation of integrin β1. Platelet‐rich plasma reversed the loss of F‐actin integrity and decrease of F‐actin/G‐actin ratio in osteoblasts in the presence of gingipains. By contrast, the effects of platelet‐rich plasma were abrogated by knockdown of integrin β1. The platelet‐rich plasma failed to reduce cell apoptosis and reorganize the cytoskeleton after knockdown of integrin β1. In conclusion, platelet‐rich plasma inhibits gingipain‐induced osteoblast apoptosis and actin cytoskeleton disruption by upregulating integrin β1 expression.     

PAX3 silencing inhibits prostate cancer progression through the suppression of the TGF‐β/Smad signaling axis

Multiple studies have confirmed the pro‐oncogenic effects of PAX3 in an array of cancers, but its role in prostate cancer (PCa) remains largely undefined. The aim of this study is to investigate the role of PAX3 in PCa. PAX3 expression was compared between PCa tumor tissue and nontumor tissues and PCa cell lines and normal prostate epithelial cells (PNT2) by western blot analysis and immunohistochemistry staining. MTT and immunofluorescence assays were used to detect PCa cell proliferation. Flow cytometry was used to evaluate cell apoptosis in PCa. Transwell assays were used for the determination of cell migration and PCa cell invasion. PAX3 expression was higher in PCa tissues and human PCa cell lines. Moreover, PAX3 silencing inhibited the proliferation, metastasis, and epithelial–mesenchymal transition (EMT) of PCa cells, and increased the rates of apoptosis. PAX3 silencing inhibited transforming growth factor‐β (TGF‐β)/Smad signaling in PCa cells. The effects of si‐PAX3 on the proliferation, apoptosis, metastasis, and EMT of PCa cells were alleviated by TGF‐β1 treatment. PAX3 silencing inhibits PCa progression through the inhibition of TGF‐β/Smad signaling. This reveals PAX3 as a novel biomarker and therapeutic target for future PCa treatments.     

Morphology,Morphogenesis, and Phylogeny of Urosoma caudata (Ehrenberg, 1833) Berger, 1999 (Ciliophora,Hypotrichia) based on a Chinese Population

We report the morphology and morphogenesis of Urosoma caudata (Ehrenberg, 1833) Berger, 1999 based on in vivo observation and protargol impregnation and provide an improved diagnosis of U. caudata based on previous and current work. Urosoma caudata differs from its congeners mainly by the combination of the following features: tail‐like posterior end, colorless cortical granules, and two macronuclear nodules. Urosoma caudata shares most of the ontogenetic features with its congeners: the oral primordium of the opisthe develops apokinetally, and the frontal‐ventral‐transverse cirral anlagen develop in five streaks. However, a unique morphogenetic characteristic is recognizable: the anlagen of three dorsal kineties occur de novo to the left of the parental structures differing from their intrakinetal origin in other Urosoma species. The first record of the 18S rRNA gene sequence for the species is also provided. Phylogenetic analyses based on 18S rRNA gene sequence data suggest that the genus Urosoma is a nonmonophyletic group.     

Rainfall manipulation experiments as simulated by terrestrial biosphere models: Where do we stand?

Changes in rainfall amounts and patterns have been observed and are expected to continue in the near future with potentially significant ecological and societal consequences. Modelling vegetation responses to changes in rainfall is thus crucial to project water and carbon cycles in the future. In this study, we present the results of a new model‐data intercomparison project, where we tested the ability of 10 terrestrial biosphere models to reproduce the observed sensitivity of ecosystem productivity to rainfall changes at 10 sites across the globe, in nine of which, rainfall exclusion and/or irrigation experiments had been performed. The key results are as follows: (a) Inter‐model variation is generally large and model agreement varies with timescales. In severely water‐limited sites, models only agree on the interannual variability of evapotranspiration and to a smaller extent on gross primary productivity. In more mesic sites, model agreement for both water and carbon fluxes is typically higher on fine (daily–monthly) timescales and reduces on longer (seasonal–annual) scales. (b) Models on average overestimate the relationship between ecosystem productivity and mean rainfall amounts across sites (in space) and have a low capacity in reproducing the temporal (interannual) sensitivity of vegetation productivity to annual rainfall at a given site, even though observation uncertainty is comparable to inter‐model variability. (c) Most models reproduced the sign of the observed patterns in productivity changes in rainfall manipulation experiments but had a low capacity in reproducing the observed magnitude of productivity changes. Models better reproduced the observed productivity responses due to rainfall exclusion than addition. (d) All models attribute ecosystem productivity changes to the intensity of vegetation stress and peak leaf area, whereas the impact of the change in growing season length is negligible. The relative contribution of the peak leaf area and vegetation stress intensity was highly variable among models.     

Deceptive pollination of Calanthe by skippers that commonly act as nectar thieves

Flowers have developed different strategies to attract pollinators through visual or olfactory signals. Most flowers offer pollinators a reward (e.g. nectar and pollen) for the pollination service. However, one‐third of Orchidaceae have been shown not to provide a reward. Calanthe are terrestrial orchids distributed throughout China, Nepal, Japan and tropical Asia. Despite its high diversity, the pollination biology of Calanthe remains largely unknown, even though it is an important aspect of plant conservation. In the study, through field surveying, there were three Hesperiidae butterflies pollinating two species of Calanthe and the pollination behavior differed between the two species of Calanthe, which might lead to different fruit setting rates. There was no nectar in the flowers of the two species, indicating deceptive pollination. Using a glass cylinder experiment, it was deduced that the two species of Calanthe were most likely to attract pollinators by generalized food deception. Interestingly, Hesperiidae butterflies were traditionally thought to be nectar thieves and generally do not transmit pollinia. However, our findings showed that, in this case, the thieves were deceived by the plants and pollinated them for free.     

The impacts of warming and nitrogen addition on competitive ability of native and invasive populations of Plantago virginica

全球变化因子(如增温和氮沉降)可能会影响生物入侵,但是这些因子如何影响入侵物种的表现并进一步调节入侵物种与本地竞争者之间的相互作用仍不清楚。本文通过为期五个月的温室实验,研究了增温(开顶式增温箱,+0.62°C)和氮添加(4.2 g N m⁻²)对入侵物种北美 车前(Plantago virginica)原产地和入侵地种群与本地车前草(Plantago asiatica)竞争的影响。实验结果表明,在增温及其与氮添加处理(W × N) 的相互作用下,P. virginica的入侵种群(PV-In)和原产地种群(PV-Na)在与本地竞争者P. asiatica竞争时具有不同的生物量分配策略。其中,PV-Na在与P. asiatica竞争时增加了地下生物量,而PV-In增加了地上生物量。我们还发现,P. virginica对增温和氮添加比P. asiatica的反应更强 烈。增温显著降低了P. virginica的竞争能力,这表明P. virginica比P. asiatica对增温的响应更为敏感。同样,在竞争条件下,氮添加及 其和增温交互作用减少了PV-In地下生物量,但增加了PV-Na地上和总生物量。这些发现表明,P. virginica在入侵过程中改变了生物量分配 策略,PV-In展示出更具弹性的竞争能力以适应环境变化(特别是增温)。这些发现可能有助于我们预测气候变化下的植物入侵并制定相应的 管理策略。     

Fluorescence characterization and microbial degradation of dissolved organic matter leached from salt marsh plants in the Yellow River Delta

盐沼植被是沿海水体中溶解有机物(Dissolved Organic Matter, DOM)的重要贡献者。然而,不同盐沼植物释放DOM的动力学特征尚缺乏系统研究和比较。黄河三角洲湿地是中国东海岸面积最大,保护最完善的沿海生态系统之一。本论文研究了2016年10月从黄河三角洲(Yellow River Delta, YRD)盐沼中采集的三种常见沼泽植物(芦苇(Phragmites australis),碱蓬(Suaeda salsa)和獐茅(Aeluropus littoralis)的DOM释放过程。通过测定溶解有机碳(Dissolved Organic Carbon, DOC)和溶解氮(Dissolved Nitrogen, DN)发现,植物叶片释放的DOM浓度远高于其根和茎。在27天的培养期内,平均有15%的生物碳和30%的生物氮以DOC和DN的形式通过植物叶片释放。从植物中释放的DOM非常不稳定,在27天的培养期内,细菌共消耗了92.4%–98.1%的DOC和88.0%–94.6%的DN。植物释放DOM的荧光特性表明,发色溶解的有机物(Chromophoric Dissolved Organic Matter, CDOM)是DOM的主要组分,而类蛋白组分是植物释放CDOM的主要组分。细菌的降解作用改变了DOM的荧光性质和化学组成。上述的室内研究结果得到了实地调查的充分支撑,表明在深秋时期黄河口湿地有大量DOM溢出。本研究结果表明,盐沼植物释放的DOM是沼泽和沿海水域DOC和DN的重要来源,而且易降解DOC和DN为黄河口湿地和邻近沿海水域中的微生物群落提供了重要的食物来源。