唾液酸对正常造血细胞及白血病细胞增殖分化的影响

本实验以测定细胞电泳率(EPM)反映细胞表面唾液酸相对含量。发现胎肝细胞电泳率明显高于成年骨髓细胞,经神经氨酸酶(NA)处理胎肝细胞、骨髓细胞、L_(801)急性白血病细胞和KCL-22慢性白血病细胞后,细胞EPM均明显下降。细胞集落数及细胞形态学检测表明,NA处理后,多向造血干细胞(CFU-S)增殖能力减弱,向粒系的分化增强;KCL-22细胞生成的集落数明显减少,成熟细胞的比例明显增加。     

基于转录组平台的蛤仔微卫星标记筛选

以菲律宾蛤仔转录组测序所得拼接序列为基础,采用MISA软件进行微卫星分析,对其中的145个微卫星位点进行引物设计,得到具有清晰扩增条带的微卫星位点58个。对大连庄河野生蛤仔群体的扩增结果表明,18个位点显示单态性,40个位点表现为多态性。该群体40个多态性微卫星位点得到的等位基因数在2—6之间,平均等位基因数为3.4250±0.9718,观测杂合度和期望杂合度分别在0.0000—1.0000和0.0615—0.7996之间,平均值分别为0.2727±0.2272和0.4739±0.1902,群体平均Nei指数为0.4664±0.1872。多态信息含量(PIC)在0.0586—0.7529之间,平均值为0.4148±0.1707,其中16个微卫星位点的PIC值大于0.5,为高度多态性,15个位点0.25PIC0.5,为中度多态性,其余9个为低度多态性。经Sequential Bonferroni校正的Hardy-Weinberg平衡检验,有10个位点尚未偏离平衡。基于转录组平台筛选微卫星标记的方法,在很大程度上推动了DNA分子标记的开发。研究开发的微卫星标记可用于蛤仔群体遗传学、遗传连锁图谱构建及其他相关研究,为蛤仔分子标记辅助育种及群体种质保护等工作提供技术支持。     

氮添加对高寒草甸土壤微生物呼吸及其温度敏感性的影响

土壤氮素的可利用性是控制土壤微生物呼吸的重要因素之一,大量研究已经表明增加土壤活性氮的含量可以降低微生物呼吸,但是土壤氮输入对土壤微生物呼吸温度敏感性的影响还不清楚。以青藏高原高寒草甸为研究对象,通过野外施氮试验和室内控制试验相结合的方式,在5℃、15℃和25℃条件下对3种施氮水平的土壤(对照,0g N m~(-2)a~(-1);低氮,5g N m~(-2)a~(-1);高氮,15g N m~(-2)a~(-1))进行培养,探讨土壤微生物呼吸及其温度敏感性对不同氮添加水平的响应情况。结果表明:(1)3个温度培养下的土壤微生物呼吸速率和累积碳释放量均随施氮量的增加而显著降低(P0.05);(2)氮添加对5℃和15℃培养条件下的微生物呼吸温度敏感性没有显著影响,但显著地增加了15℃和25℃培养条件下的微生物呼吸温度敏感性(P0.05);(3)线性相关分析表明,土壤累积碳释放量与土壤有机碳的难降解性显著负相关(P0.05),而15℃和25℃培养条件下的微生物呼吸温度敏感性与土壤有机碳的难降解性显著正相关(P0.05)。结果表明,在全球气候变暖的背景下,土壤氮输入将增加预测青藏高原高寒草甸地区土壤碳排放的不确定性。     

Polymorphism of Avian Leukosis Virus Subgroup E Loci Showing Selective Footprints in Chicken

Avian leukosis virus subgroup E (ALVE) is a family of endogenous retroviruses in the chicken genome. To investigate the genetic consequences of chicken domestication, we analyzed 18 ALVE loci in red jungle fowls, layers, broilers, and Chinese indigenous chickens. None of the ALVE loci tested were found in red jungle fowls, but 12 were present in domestic chickens. ALVE1 and ALVE16 are found in regions of the genome that harbor quantitative trait loci (QTL) affecting egg production traits. ALVE1 was fixed and ALVE16 was detected only in layers. By contrast, ALVE-b1, ALVE-b5, ALVE-b6, and ALVE-b8 integrated into regions of the genome that harbor QTL affecting meat production traits. Carrier frequencies of these four ALVE loci were high in broilers and low in Chinese local chickens; the loci were not found in the layers. This study demonstrated that insertionally polymorphic ALVE loci can illustrate the selective footprints in the chicken genome.     

小型猪血浆中二丙酸倍他米松及其代谢物倍他米松的LC-MS/MS 同时测定方法的建立及在药动学研究中的应用

目的：建立同时测定小型猪血浆中二丙酸倍他米松及其代谢物倍他米松的LC-MS/MS 法,并研究小型猪皮肤外用二丙酸倍他米松乳膏后,二丙酸倍他米松及倍他米松的药动学特征。方法：血浆样品经酸化后以乙醚- 环己烷（4 ∶ 1）提取,LC-MS/MS 分析,以Hedera ODS-2（150 mm×2.1 mm,5 μm）为分析柱,流动相为5 mmol?L-1 醋酸铵水溶液（含0.1% 乙酸）– 甲醇,梯度洗脱。二丙酸倍他米松、倍他米松及内标布地奈德的监测离子对分别为m /z 563.2（[M+CH3COO]-）→ 483.1、m /z 451.2（[M+CH3COO]-）→ 361.0 和m /z 489.3（[M+CH3COO]-）→ 357.1。对小型猪外用二丙酸倍他米松乳膏后其血浆中二丙酸倍他米松及代谢物倍他米松的浓度进行测定,并计算主要药动学参数。结果：二丙酸倍他米松血药浓度在26.85~644.4 ng?L-1 范围内线性关系良好,倍他米松血药浓度在10.62~637.2 ng?L-1 范围内线性关系良好。结论：本方法专属性强、简便、灵敏,可用于血浆样本中二丙酸倍他米松及其代谢物倍他米松的测定及药动学研究。     

Structure-activity-relationship studies of conformationally restricted analogs of combretastatin A-4 derived from SU5416

A series of combretastatin A-4 analogs derived from the ATP competitive, VEGF receptor tyrosine kinase inhibitor, SU5416 were synthesized. The cytotoxic effects of the analogs were evaluated against PC-3 and MDA-MB-231 cancer cell lines, as well as their abilities to inhibit tubulin polymerization. Results are compared to those of compound 1, our lead compound previously reported.     

Conformational Changes in the Lower Palm Domain of ASIC1a Contribute to Desensitization and RFamide Modulation

Acid-sensing ion channel 1a (ASIC1a) is a proton-gated cation channel that contributes to fear and pain as well as neuronal damage following persistent cerebral acidosis. Neuropeptides can affect acid-induced neuronal injury by altering ASIC1a inactivation and/or steady-state desensitization. Yet, exactly how ASIC1a inactivation and desensitization occur or are modulated by peptides is not completely understood. We found that regions of the extracellular palm domain and the β_11-12 linker are important for inactivation and steady-state desensitization of ASIC1a. The single amino acid substitutions L280C and L415C dramatically enhanced the rate of inactivation and altered the pH-dependence of steady-state desensitization. Further, the use of methanethiosulfonate (MTS) reagents suggests that the lower palm region (L280C) undergoes a conformational change when ASIC1a transitions from closed to desensitized. We determined that L280C also displays an altered response to the RFamide peptide, FRRFamide. Further, the presence of FRRFamide limited MTS modification of L280C. Together, these results indicate a potential role of the lower palm domain in peptide modulation and suggest RFamide-related peptides promote conformational changes within this region. These data provide empirical support for the idea that L280, and likely this region of the central vestibule, is intimately involved in channel inactivation and desensitization.     

Evaluation of protein extraction protocols for 2DE in marine ecotoxicoproteomics

In ecotoxicoproteomics, an accurate and reproducible extraction of proteins is a critical step for 2DE analysis and further protein identification using MS. The criteria for the assessment of protein extraction quality include protein yield, protein spots resolved in a 2DE gel, matched protein spots in replicate gels, reproducibility, and compatibility with MS. In this work, we evaluated three protein extraction systems, straightforward lysis buffer, trichloroacetic acid–acetone, and TRIzol reagent with some modifications, for the protein extraction from three animal species including mussel Mytilus galloprovincialis, flounder Paralichthys olivaceus, and polychaete Nereis diversicolor used in marine ecotoxicology. Our results indicated that these methods could extract significantly different protein profiles. The method using TRIzol reagent resulted in the most matched protein spots resolved in four replicate 2DE gels and highest reproducibilities for the gill of M. galloprovincialis and liver of P. olivaceus. However, a modified trichloroacetic acid–acetone solvent system was best for the whole soft tissue of N. diversicolor. This work provides the fundamental information of the extraction quality of protein extraction protocols from different marine animals, which may facilitate the selection of a suitable protein extraction protocol for ecotoxicoproteomics.     

Pseudolaric acid B ameliorates synovial inflammation and vessel formation by stabilizing PPARγ to inhibit NF-κB signalling pathway

Synovial macrophage polarization and inflammation are essential for osteoarthritis (OA) development, yet the molecular mechanisms and regulation responsible for the pathogenesis are still poorly understood. Here, we report that pseudolaric acid B (PAB) attenuated articular cartilage degeneration and synovitis during OA. PAB, a diterpene acid, specifically inhibited NF-κB signalling and reduced the production of pro-inflammatory cytokines, which further decreased M1 polarization and vessel formation. We further provide in vivo and in vitro evidences that PAB suppressed NF-κB signalling by stabilizing PPARγ. Using PPARγ antagonist could abolish anti-inflammatory effect of PAB and rescue the activation of NF-κB signalling during OA. Our findings identify a previously unrecognized role of PAB in the regulation of OA and provide mechanisms by which PAB regulates NF-κB signalling through PPARγ, which further suggest targeting synovial inflammation or inhibiting vessel formation at early stage could be an effective preventive strategy for OA.     

Histological characteristics of exercise-induced skeletal muscle remodelling

This study aims to analyse the pathological features of skeletal muscle injury repair by using rats to model responses to different exercise intensities. Eighty-four rats were randomly divided into five groups for treadmill exercise. The short-term control, low-intensity, medium-intensity and high-intensity groups underwent gastrocnemius muscle sampling after 6, 8 and 12 weeks of exercise. The long-term high-intensity group underwent optical coherence tomography angiography and sampling after 18 weeks of exercise. RNA sequencing was performed on the muscle samples, followed by the corresponding histological staining. Differentially expressed genes were generally elevated at 6 weeks in the early exercise stage, followed by a decreasing trend. Meanwhile, the study demonstrated a negative correlation between time and the gene modules involved in vascular regulation. The modules associated with muscle remodelling were positively correlated with exercise intensity. Although the expression of many genes associated with common angiogenesis was downregulated at 8, 12 and 18 weeks, we found that muscle tissue microvessels were still increased, which may be closely associated with elevated sFRP2 and YAP1. During muscle injury-remodelling, angiogenesis is characterized by significant exercise time and exercise intensity dependence. We find significant differences in the spatial distribution of angiogenesis during muscle injury-remodelling, which be helpful for the future achievement of spatially targeted treatments for exercise-induced muscle injuries.