Pathogenic analysis of coxsackievirus A10 in rhesus macaques

Coxsackievirus A10 (CV-A10) is one of the etiological agents associated with hand, foot and mouth disease (HFMD) and also causes a variety of illnesses in humans, including pneumonia, and myocarditis. Different people, particularly young children, may have different immunological responses to infection. Current CV-A10 infection animal models provide only a rudimentary understanding of the pathogenesis and effects of this virus. The characteristics of CV-A10 infection, replication, and shedding in humans remain unknown. In this study, rhesus macaques were infected by CV-A10 via respiratory or digestive route to mimic the HFMD in humans. The clinical symptoms, viral shedding, inflammatory response and pathologic changes were investigated in acute infection (1–11 day post infection) and recovery period (12–180 day post infection). All infected rhesus macaques during acute infection showed obvious viremia and clinical symptoms which were comparable to those observed in humans. Substantial inflammatory pathological damages were observed in multi-organs, including the lung, heart, liver, and kidney. During the acute period, all rhesus macaques displayed clinical signs, viral shedding, normalization of serum cytokines, and increased serum neutralizing antibodies, whereas inflammatory factors caused some animals to develop severe hyperglycemia during the recovery period. In addition, there were no significant differences between respiratory and digestive tract infected animals. Overall, all data presented suggest that the rhesus macaques provide the first non-human primate animal model for investigating CV-A10 pathophysiology and assessing the development of potential human therapies.     

CD146 as a promising therapeutic target for retinal and choroidal neovascularization diseases

Science China Life Sciences - Blood vessel dysfunction causes several retinal diseases, including diabetic retinopathy, familial exudative vitreoretinopathy, macular degeneration and choroidal...     

替米沙坦调控miR-495-3p/心肌细胞增强因子2A通路减轻缺氧诱导的神经细胞PC12损伤

目的探讨替米沙坦（TM）调控miR-495-3p/心肌细胞增强因子2A （MEF2A）通路对缺氧诱导PC12细胞损伤的影响和机制。 方法将PC12细胞进行正常培养（对照）,缺氧（缺氧24 h）,缺氧+ 0.1、1、10 μg/mL TM、缺氧+ miR-NC （转染miR-NC）,缺氧+miR-495-3p （转染miR-495-3p模拟物）,缺氧+TM+anti-miR-NC （转染anti-miR-NC,10 μg/mL TM）和缺氧+ TM+anti-miR-495-3p （转染anti-miR-495-3p,10 μg/mL TM）处理。酶联免疫吸附实验（ELISA）检测乳酸脱氢酶（LDH）漏出量和超氧化物歧化酶（SOD）的活性,流式细胞术检测细胞凋亡,实时荧光定量PCR （RT-qPCR）和Western blot检测miR-495-3p、心肌细胞增强因子2A （MEF2A）表达水平。两组间比较采用t检验,多组间比较采用单因素方差分析,组间两两比较采用LSD-t检验。 结果与对照比较,缺氧处理的PC12细胞LDH漏出率[（9.46±0.97）﹪比（45.69±4.31）﹪]、细胞凋亡率[（5.36±0.54）﹪比（28.36±2.41）﹪]、MEF2A mRNA（1.00±0.08比2.74±0.26）和MEF2A蛋白表达水平（0.39±0.03比0.87±0.06）均升高;SOD活性[（12.24 ±1.13）比（5.13±0.52 ）U/mL）]和miR-495-3p表达水平（1.00±0.08比0.35±0.03）均降低,差异有统计学意义（P均< 0.05）。与缺氧处理比较,缺氧+0.1、1、10 μg/mL TM干预的PC12细胞LDH漏出率[（45.69±4.31）﹪比（32.14±3.84）﹪、（23.54±3.17）﹪、（16.87±1.46）﹪]、细胞凋亡率[（28.36±2.41）﹪比（22.46±2.31）﹪、（17.14±1.65）﹪、（10.23±1.12）﹪]、MEF2A mRNA（2.74±0.26比2.26±0.23、1.87±0.19、1.34±0.18）和MEF2A蛋白表达水平（0.87±0.06比0.75±0.05、0.63±0.04、0.46±0.03）均降低;SOD活性[（5.13±0.52）比（6.87±0.69 ）、（8.01±0.81）、（10.12±1.02）U/mL]、miR-495-3p表达水平（0.35±0.03比0.49±0.04、0.61±0.06、0.83±0.07）均升高,差异有统计学意义（P均< 0.05）。与缺氧+ miR-NC比较,缺氧+ miR-495-3p的PC12细胞LDH漏出率[（46.87±4.28）﹪比（19.65±1.87）﹪]和细胞凋亡率[（28.38±2.44）﹪比（12.36±1.25）﹪]均降低,SOD活性[（5.15±0.51）比（9.67±0.97）U/mL]升高,差异有统计学意义（P均< 0.05）。与缺氧+TM+anti-miR-NC比较,缺氧+TM+anti-miR-495-3p的PC12细胞LDH漏出率[（17.64±1.79）﹪比（32.69±3.57）﹪]和细胞凋亡率[（10.98±1.75）﹪比（22.64±2.13）﹪]均升高,SOD活性[（12.63±1.27）比（7.32±0.71）U/mL]降低,差异有统计学意义（P均< 0.05）。 结论TM通过上调miR-495-3p/MEF2A通路对缺氧诱导的PC12细胞损伤具有保护作用。     

NUCLEAR PORE ANCHOR and EARLY IN SHORT DAYS 4 negatively regulate abscisic acid signaling by inhibiting Snf1-related protein kinase2 activity and stability in Arabidopsis

Abscisic acid (ABA) is a key regulator of plant responses to abiotic stresses, such as drought. Abscisic acid receptors and coreceptors perceive ABA to activate Snf1-related protein kinase2s (SnRK2s) that phosphorylate downstream effectors, thereby activating ABA signaling and the stress response. As stress responses come with fitness penalties for plants, it is crucial to tightly control SnRK2 kinase activity to restrict ABA signaling. However, how SnRK2 kinases are inactivated remains elusive. Here, we show that NUCLEAR PORE ANCHOR (NUA), a nuclear pore complex (NPC) component, negatively regulates ABA-mediated inhibition of seed germination and post-germination growth, and drought tolerance in Arabidopsis thaliana. The role of NUA in response to ABA depends on SnRK2.2 and SnRK2.3 for seed germination and on SnRK2.6 for drought. NUA does not directly inhibit the phosphorylation of these SnRK2s or affects their abundance. However, the NUA-interacting protein EARLY IN SHORT DAYS 4 (ESD4), a SUMO protease, negatively regulates ABA signaling by directly interacting with and inhibiting SnRK2 phosphorylation and protein levels. More importantly, we demonstrated that SnRK2.6 can be SUMOylated in vitro, and ESD4 inhibits its SUMOylation. Taken together, we identified NUA and ESD4 as SnRK2 kinase inhibitors that block SnRK2 activity, and reveal a mechanism whereby NUA and ESD4 negatively regulate plant responses to ABA and drought stress possibly through SUMOylation-dependent regulation of SnRK2s.     

Application of a luminous intensity variation fluorescent probe for the detection of ferric ions

A luminous intensity variation fluorescent probe (Probe 1) for the detection of ferric ion was developed. The quantitative range of Fe³⁺ content detected was 0–600 μM with the limit of detection at 0.76 μM. Furthermore, after 20 min of Fe³⁺ addition, the intensity of the luminescence of Probe 1 solution gradually decreased with increase in Fe³⁺ concentration. In addition, the B and G values of these images showed a linear relationship with Fe³⁺ concentration (0–500 μM). Probe 1 was successfully used for the rapid determination of Fe³⁺ concentration in real samples. This study demonstrates that Probe 1 is an excellent tool for the rapid determination of Fe³⁺ content in real samples using a smart phone without professional equipment.     

Molecular dynamics simulations provide insights into the origin of gleevec’s selectivity toward human tyrosine kinases

Protein kinases are critical drug targets against cancer. Since the discovery of Gleevec, a specific inhibitor of Abl kinase, the capability of this drug to distinguish between Abl and other tyrosine kinases, such as Src, has been intensely investigated but the origin of Gleevec’s selectivity to Abl against Src is less studied. Here, we performed molecular dynamics (MD) simulations, dynamical cross-correlation matrices (DCCM), dynamical network analysis, and binding free energy calculations to explore Gleevec’s selectivity based on the crystal structures of Abl, Src, and their common ancestors (ANC-AS) and the two constructed mutation systems (AS→Abl and AS→Src). MD simulations revealed that the conformation of the phosphate-binding loop (P-loop) was altered significantly in the AS→Abl system. DCCM results unraveled that mutations increased anticorrelated motions in the AS→Abl system. Community network analysis suggested that the P-loop established special contacts in the AS→Abl system that are devoid in the AS→Src system. The binding free energy calculations unveiled that the affinity of Gleevec to AS→Abl increased to near the Abl level, whereas its affinity to AS→Src decreased to near the Src level. Analysis of individual residue contributions showed that the differences were located mainly at the P-loop. This study is valuable for understanding the sensitivity of Gleevec to human tyrosine kinases.

Communicated by Ramaswamy H. Sarma     

Identification of potent,selective and orally bioavailable phenyl ((R)-3-phenylpyrrolidin-3-yl)sulfone analogues as RORγt inverse agonists

An X-ray crystal structure of one of our previously discovered RORγt inverse agonists bound to the RORγt ligand binding domain revealed that the cyclohexane carboxylic acid group of compound 2 plays a significant role in RORγt binding, forming four hydrogen bonding and ionic interactions with RORγt. SAR studies centered around the cyclohexane carboxylic acid group led to identification of several structurally diverse and more potent compounds, including new carboxylic acid analogues 7 and 20, and cyclic sulfone analogues 34 and 37. Notably, compounds 7 and 20 were found to maintain the desirable pharmacokinetic profile of 2.