Age-dependent changes in the gut microbiota and serum metabolome correlate with renal function and human aging

Human aging is invariably accompanied by a decline in renal function, a process potentially exacerbated by uremic toxins originating from gut microbes. Based on a registered household Chinese Guangxi longevity cohort (n = 151), we conducted comprehensive profiling of the gut microbiota and serum metabolome of individuals from 22 to 111 years of age and validated the findings in two independent East Asian aging cohorts (Japan aging cohort n = 330, Yunnan aging cohort n = 80), identifying unique age-dependent differences in the microbiota and serum metabolome. We discovered that the influence of the gut microbiota on serum metabolites intensifies with advancing age. Furthermore, mediation analyses unveiled putative causal relationships between the gut microbiota (Escherichia coli, Odoribacter splanchnicus, and Desulfovibrio piger) and serum metabolite markers related to impaired renal function (p-cresol, N-phenylacetylglutamine, 2-oxindole, and 4-aminohippuric acid) and aging. The fecal microbiota transplantation experiment demonstrated that the feces of elderly individuals could influence markers related to impaired renal function in the serum. Our findings reveal novel links between age-dependent alterations in the gut microbiota and serum metabolite markers of impaired renal function, providing novel insights into the effects of microbiota-metabolite interplay on renal function and healthy aging.     

Smooth muscle-specific HuR knockout induces defective autophagy and atherosclerosis

Human antigen R (HuR) is a widespread RNA-binding protein involved in homeostatic regulation and pathological processes in many diseases. Atherosclerosis is the leading cause of cardiovascular disease and acute cardiovascular events. However, the role of HuR in atherosclerosis remains unknown. In this study, mice with smooth muscle-specific HuR knockout (HuR^SMKO) were generated to investigate the role of HuR in atherosclerosis. HuR expression was reduced in atherosclerotic plaques. As compared with controls, HuR^SMKO mice showed increased plaque burden in the atherosclerotic model. Mechanically, HuR could bind to the mRNAs of adenosine 5′-monophosphate-activated protein kinase (AMPK) α1 and AMPKα2, thus increasing their stability and translation. HuR deficiency reduced p-AMPK and LC3II levels and increased p62 level, thereby resulting in defective autophagy. Finally, pharmacological AMPK activation induced autophagy and suppressed atherosclerosis in HuR^SMKO mice. Our findings suggest that smooth muscle HuR has a protective effect against atherosclerosis by increasing AMPK-mediated autophagy.Subject terms: Cardiovascular diseases, Pathogenesis     

表面活性剂对嗜盐嗜碱硫碱弧菌D301生成及利用硫颗粒的影响

[背景]微生物脱硫是脱除气体中硫化氢的一种有效方法,其中,硫颗粒的生成与代谢是控制生物脱硫效率的关键,但目前相应的控制方法很少.[目的]研究不同种类表面活性剂对硫碱弧菌D301生成及利用硫颗粒的影响.[方法]通过摇床培养,利用X射线衍射、冷场发射扫描电镜、能谱分析及傅里叶红外光谱对硫颗粒进行表征.[结果]单质硫主要以S...     

高效液相尺寸排阻色谱-多角度激光散射定量检测灭活禽流感病毒抗原中完整病毒颗粒

本研究旨在建立一种灭活禽流感病毒原料液中完整病毒颗粒准确定量的方法。针对直接采用高效液相尺寸排阻色谱法（high performance size exclusion chromatography，HPSEC）检测灭活禽流感病毒原液存在杂质干扰的问题，首先以H5N8型抗原为对象，分别考察了聚乙二醇（polyethylene glycol，PEG）沉淀和离子交换色谱法（ion exchange chromatography，IEC）进行预处理。在优化条件下，经DEAE FF阴离子交换层析纯化预处理，杂蛋白去除率为86.87%，病毒血凝回收率为100%。HPSEC分析预处理后的样品，8.5–10.0 min处色谱峰样品电泳检测显示主要为H5N8病毒蛋白，动态光散射分析平均粒径为127.7 nm，推测为完整病毒特征峰；在IEC预处理后的样品中加入抗体进行HPSEC检测，8.5-10.0 min处特征峰消失，显示IEC预处理有效去除了杂质干扰。通过将HPSEC与多角度激光散射技术（multi-angle laser scattering technique，MALLS）联用，可以准确获得样品中完整病毒颗粒的数量，且病毒颗粒数与色谱峰面积具有良好线性关系（R²=0.997）。建立的IEC预处理-HPSEC-MALLS检测方法应用于其他亚型（H7N9）、批次和浓度的病毒原液中完整病毒颗粒数的准确检测，均具有良好适用性，且重复性好，相对标准偏差（relative standard deviation，RSD）<5%，n=3。     

ESCRT-III component OsSNF7.2 modulates leaf rolling by trafficking and endosomal degradation of auxin biosynthetic enzyme OsYUC8 in rice

The endosomal sorting complex required for transport (ESCRT) is highly conserved in eukaryotic cells and plays an essential role in the biogenesis of multivesicular bodies and cargo degradation to the plant vacuole or lysosomes. Although ESCRT components affect a variety of plant growth and development processes, their impact on leaf development is rarely reported. Here, we found that OsSNF7.2, an ESCRT-III component, controls leaf rolling in rice (Oryza sativa). The Ossnf7.2 mutant rolled leaf 17 (rl17) has adaxially rolled leaves due to the decreased number and size of the bulliform cells. OsSNF7.2 is expressed ubiquitously in all tissues, and its protein is localized in the endosomal compartments. OsSNF7.2 homologs, including OsSNF7, OsSNF7.3, and OsSNF7.4, can physically interact with OsSNF7.2, but their single mutation did not result in leaf rolling. Other ESCRT complex subunits, namely OsVPS20, OsVPS24, and OsBRO1, also interact with OsSNF7.2. Further assays revealed that OsSNF7.2 interacts with OsYUC8 and aids its vacuolar degradation. Both Osyuc8 and rl17 Osyuc8 showed rolled leaves, indicating that OsYUC8 and OsSNF7.2 function in the same pathway, conferring leaf development. This study reveals a new biological function for the ESCRT-III components, and provides new insights into the molecular mechanisms underlying leaf rolling.     

重金属离子对酵母影响的研究

本文探讨了培养基中不同浓度的重金属离子（Ｃｒ^＋２、Ｐｂ^＋２）对酵母的影响。实验结果表明,重金属离子的浓度越高,酵母菌的一系列生理生化指标：如每个培养皿的菌落数、细胞直径、蛋白质、核酸及可溶性糖的含量都有不同程度的降低。     

Development of semi-ab initio interionic potential for CaO and MgO

In this paper, we propose a novel method to derive the interionic potentials for CaO and MgO in conjunction with ab initio calculation and empirical three-body interaction. By using the Chen–Mobius lattice inversion, the pairwise interaction between cations and anions can be evaluated from multiple virtual structures. The quantum-chemistry calculation is carried out to derive the short-range potential for the same species of ions. Empirical three-body interactions are then adopted to heal the drawbacks arising from purely pairwise potential, such as Cauchy relation. The proposed potential is verified by molecular dynamics simulations of some primary properties, including pressure and temperature dependence of lattice constant, elastic constants and phase transition of CaO and MgO. Simulation results are in good agreement with the existing experimental data and ab initio calculations, showing that the developed potentials are valid over a wide range of interionic separations. It is believed that this approach can be readily extended into other materials.     

Carboxyl-Dominant Oxygen Rich Carbon for Improved Sodium Ion Storage: Synergistic Enhancement of Adsorption and Intercalation Mechanisms

Oxygen-containing groups in carbon materials have been shown to affect the carbon anode performance of sodium ion batteries; however, precise identification of the correlation between specific oxygen specie and Na⁺ storage behavior still remains challenging as various oxygen groups coexist in the carbon framework. Herein, a postengineering method via a mechanochemistry process is developed to achieve accurate doping of (20.12 at%) carboxyl groups in a carbon framework. The constructed carbon anode delivers all-round improvements in Na⁺ storage properties in terms of a large reversible capacity (382 mAg⁻¹ at 30 mA g⁻¹), an excellent rate capability (153 mAg⁻¹ at 2 A g⁻¹) as well as good cycling stability (141 mAg⁻¹ after 2000 cycles at 1.5 A g⁻¹). Control experiments, kinetic analysis, density functional theory calculations, and operando measurements collectively demonstrate that carboxyl groups not only act as active sites for Na⁺ capacitive adsorption through suitable electrostatic interactions, but also gradually expand d-spacing by inducing a repulsive force between carbon layers with Na⁺ preadsorbed, and hence facilitate diffusion-controlled Na⁺ insertion process. This work provides a new insight in the rational tunning of oxygen-containing groups in carbon for boosting reversible Na⁺ storage through a synergy of adsorption and intercalation processes.