Effect of inhibiting mTOR signaling pathway on p-AKT1 molecule in lung of juvenile SD rats and its significance

AIM:To investigate the effect of inhibiting mammalian target of rapamycin (mTOR) signaling pathway on phosphorylated AKT1 (p-AKT1) during lung injury induced by hyperoxygen in juvenile SD rats and its significance. METHODS:The SD rats (3 weeks old, n=72) were randomly divided into air + saline group, hyperoxia + saline group, hyperoxia + OSI-027 group, and hyperoxia + rapamycin group (n=18 in each group). The animal model was constructed by continuous intervention with a 90% volume fraction of oxygen, and normal saline, OSI-027 and rapamycin were administered by intraperitoneal injection at 1, 3, 6, 8, 10 and 13 d of the observation period. At 3, 7 and 14 d, the changes of the body weight, wet/drg weight ratio (W/D), lung histopathology, alveolar septal width and lung injury score were measured, and immunohistochemistry and Western blot were used to detect the distribution and protein levels of phosphorylated S6K1 (p-S6K1) and p-AKT1 in the lung tissues. RESULTS:Compared with air group, the body weight of the rats in hyperoxia group was significantly decreased (P<0.05), the lung W/D was increased in the acute phase of lung injury (P<0.05), and the alveolar septal width and lung injury scores were significantly increased (P<0.05). The p-S6K1 positive cells in the lung tissues were increased (P<0.05), p-AKT1 positive cells were decreased (P<0.05), p-S6K1 protein was increased significantly (P<0.01), and p-AKT1 protein was decreased significantly (P<0.01). Compared with hyperoxia group, the lung tissue injury in hyperoxia + OSI-027 group was alleviated (P<0.05), p-S6K1 positive cells in the lung tissues was decreased (P<0.05), p-AKT1 positive cells was increased (P<0.05), p-S6K1 protein level was significantly decreased (P<0.05), and p-AKT1 protein level was increased (P<0.05). Hyperoxia+rapamycin further aggravated lung injury (P<0.05), p-S6K1 positive cells decreased (P<0.05), p-AKT1 positive cells increased (P<0.05), p-S6K1 protein levels decreased significantly (P<0.05), and p-AKT1 protein levels increased significantly (P<0.05). Compared with hyperoxia + rapamycin group, the lung tissue damage was alleviated in hyperoxia + OSI-027 group (P<0.05), p-AKT1 positive cells in the lung tissues were decreased (P<0.05), and p-AKT1 protein level was decreased (P<0.05). CONCLUSION:p-AKT1 may be involved in the development of hyperoxia-induced lung injury, and its regulation mechanism may be related to the mTOR signaling pathway. In hyperoxia-induced lung injury, the protein level of p-AKT1 is decreased, and mTOR inhibitors increase the p-AKT1 protein. However, only the mTORC1/2 dual inhibitor OSI-027 alleviates the hyperoxia-induced fibrosis in juvenile SD rats.     

Effects of PI3K/AKT signaling pathway on polarization of M2 macrophages induced by SjCystatin

AIM: To investigate the subtype of M2 macrophages induced by Schistosoma japonicum cystatin (SjCystatin) and to determine the mechanism underlying these effects.METHODS: The releases of IL-10 and IL-12, and the expression of macrophage subtype markers LIGHT (M2b) and Arg-1 (M2a+M2c) were assessed by ELISA, RT-qPCR and Western blot. The phosphorylation level of AKT was assessed by Western blot.RESULTS: SjCystatin promoted the continuous increase in IL-10 level at 6 h, 12 h and 24 h, and increased the amount of mRNA and protein expression of LIGHT, but down-regulated the amount of mRNA and protein expression of AKT. The addition of PI3K/AKT inhibitor reduced the release of IL-10 at 12 h and 24 h, reduced the mRNA and protein expression of LIGHT at 24 h, up-regulated the mRNA and protein expression of Arg-1 at 24 h, and decreased the phosphorylation level of AKT.CONCLUSION: SjCystatin promotes the differentiation of M2 macrophage to M2b macrophage subtype, and the PI3K/AKT signaling pathway is involved in this process.     

粘土矿物中钾的生物活化: Ⅰ. 外生菌根

A pot experiment was Carried out to in vestigate effect of ectomycorrhizal fungi on eucalyptus growth and K bio-mobilization from soils and clay minerals,In the experiment,sands mixed with soil,KCl-satureated vermiculate and mica,respectively,were used to nurse eucalypus seedings which were nonectomycorrhized or ectomycorrhized by an ectomycorrhizal fungus Pisolithus tinctorius strain XL1(Pt XC1) isolated from a forest soil from Xichang,Sichuan Province,China,and a worldwide well-know ectomycorrhial fungus Pioslithus tinctorius strain 2144(Pt 2144) obtained in Australia.More depletion of HCl-souluble K by mycorrhizas from the soil and minerals than nomycorrhizas suggested that mycorrhizas had a great ability to mobilize K present in the interlayer and feldspar.Mycorrhizal seedlings depressed greatly K digested with HF-HClO4 from substrates after consecutive extractions of soils and minerals by water,ammonium acetate and boiling HCl,while nonmycorrhizal seedlings reduced it little if any,shwing that the mycorrhizal seedlings could mobilize and then utilize the structureal K in mineral lattice,Ectomycorrhizal fungi played a very important role not only in promoting the growth of eucalyptus seedlings but also in mobilizing K in soils and minerals.The infection of Pt XC1 led to a better growth of eucalyptus seedlings and more K accumulation in the seedlings than that of Pt 2144.The large differeces in K accumulation by the seedlings might be due to different abilityes of the two ectomycorrhizal fungi to mobilize K in intelayer and lattice pools in the clay minerals.     

氮肥对绿豆氮磷钾积累分配及产量构成因子的影响

试验于2009～2010年在沈阳农业大学进行,以半蔓生型辽绿6号和直立型辽绿8号为试材,设两个施氮处理,分别为中氮(30kg/hm2)和高氮(60kg/hm2),不施氮(0kg/hm2)为对照。并在绿豆开花期、结荚期和成熟期进行了氮磷钾分配的测定。结果表明:高氮对绿豆氮磷钾含量增加的影响较大,中氮影响则不显著;不同株型的绿豆品种都是以中氮(30kg/hm2)的产量性状表现最佳,说明中氮有利于绿豆产量的提高;辽绿6号高氮、中氮产量均高于辽绿8号的产量,说明施氮后辽绿6号比辽绿8号的增产潜力大。     

黄枝油杉ISSR-PCR反应体系的建立与优化

先运用正交设计进行初步筛选,再用单因素设计逐一优化对ISSR-PCR扩增效果有影响的Mg2+、Taq DNA聚合酶、dNTP、引物、模板DNA、循环次数及退火温度.建立了黄枝油杉的最佳反应体系和程序,即25μL体系中含2.0mmol/L的Mg2+、1.5U Taq DNA聚合酶、0.10mmol/L的dNTP、1.0μmol/L的引物、30ng的模板DNA以及2.5μL10×PCR buffer,其余的用灭菌的ddH2O补够25μL.扩增程序:94℃预变性5min;94℃变性30s,48～56℃(不同的引物,其退火温度不同,根据具体引物而定)退火45s,72℃延伸90s,以上3个步骤循环50次;最后72℃延伸7min;扩增产物放在4℃冰箱中保存.该体系和程序稳定性良好,结果可靠,可用于黄枝油杉遗传多样性分析.     

Using Soil Potassium Adsorption and Yield Response Models to Determine Potassium Fertilizer Rates for Potato Crop on a Calcareous Soil in Pakistan

Ustochrept soil was collected from a major potato-growing area in Pakistan for a potassium (K) adsorption isotherm experiment. Adsorption data were fitted to Freundlich and Langmuir adsorption models. Results showed that the Freundlich model (R²?=?0.96**) fit the data better than did the Langmuir model. Fertilizer rates were calculated based on the Freundlich model and targeted solution K levels at 0, 3, 6, 9, 12, 15, 18, 21, 24, and 27 mg K L^?1. A field experiment was then conducted on the soil to assess the effect of various soil solution K levels (0–27 mg L^?1, with K fertilizer rates at 0, 24, 49, 75, 101, 128, 155, 182, 210, and 237 kg ha^?1), on tuber yield and quality along with 300 kg N and 250 kg P₂O₅ ha^?1 as basal doses. Yield response models (linear plus plateau, quadratic, square root, quadratic plus plateau, and exponential) were used to calculate the optimal fertilizer rate for potato crop. Linear plus plateau model fit the data with less bias than the other models. There was a significant effect of K use on the yield and quality of potatoes. Potassium fertilizer application at 130 kg K ha^?1, which is equivalent to a soil solution level of 12 mg K L^?1, maximized the tuber yield of potato. However, for the improvement in tuber dry matter, reducing sugars, protein contents, and starch contents, the soil solution K level required was as high as14.62 mg L^?1 (157 kg ha^?1). Even greater rate of K, 17.74 mg L^?1 (190 kg ha^?1), was needed to maximize vitamin C content in potato.     

稻田固氮解磷解钾菌筛选及其复合菌剂对土壤培肥作用

用固氮、解磷、解钾培养基,分别从稻田土壤中分离获得9个固氮菌株(A1-A9)、7个解磷菌株(B1-B7)和6个解钾菌株(C1-C6)。对各菌株固氮、解磷、解钾能力及水稻促生效果分析表明,最突出菌株分别为A5、B2、C5;各菌株等比例混合组成复合菌剂接入灭菌稻田土壤,30 d后可使土壤总氮、有效磷、速效钾分别增加21.32%、32.17%、45.57%;初步鉴定各菌株分别为固氮菌属(Azotobacter sp.)、假单胞菌属(Pseudomonas sp.)和芽孢杆菌属(Bacillus sp.)。复合菌剂处理稻田土壤,水稻苗高、鲜重、干重及植株全氮、全磷、全钾显著优于对照组,说明筛选菌株可在稻田土壤氮、磷、钾转换及培肥过程中起重要作用。     

表达大肠杆菌K99重组干酪乳杆菌口服免疫小鼠的免疫保护性研究

利用千酪乳杆菌(Lactobacillus casei)作为抗原传递系统来刺激机体产生黏膜免疫反应,从而研制有效的黏膜疫苗预防产肠毒素性大肠杆菌(ETEC)的感染.用PCR方法扩增ETEC K99基因,克隆到L.casei细胞表面表达载体pLA中,构建了重组表达载体pLA.K99,并将其电转化至L.casei中,在MRS培养基中培养后,经SDS-PAGE、western blot检测目的蛋白的表达,间接免疫荧光分析及流式细胞术检测外源蛋白展示到菌体表面.将重组菌及空质粒菌株分别口服接种SPF级BALB/c小鼠.采集血液样品测定小鼠产生抗K99的特异性IgG,收集小鼠肺部、肠道、阴道冲洗液及粪便样品测定小鼠产生的抗K99的特异性sIgA,并对小鼠进行攻毒保护性试验,免疫组保护率在83%以上,对照组则全部死亡.     

Fluctuations in soil test values for potassium as influenced by time of sampling

Abstract

Soil samples were taken at frequent intervals in 1975 and 1976 from a factorial set of lime ‐K treatments initiated in December 1970 to determine the effect time of sampling has on K soil test values. Previous work at this site had shown wide fluctuations in K soil test values due to sample time thus necessitating a more detailed study than was previously made. Such information is necessary if accurate K fertilizer recommendations are to be made. Samples from 28 unfertilized plots showed that months of sampling significantly affected K soil test values. Soil test values for K were highest in late May and declined as the growing season progressed, remaining low until the relatively higher exchangeable K was re‐established the following spring.

Disregard for this phenomenon could result in inaccurate recommendations for K fertilizer.