FBXW7 suppresses epithelial‐mesenchymal transition and chemo‐resistance of non‐small‐cell lung cancer cells by targeting snai1 for ubiquitin‐dependent degradation

Objectives

FBXW7 acts as a tumour suppressor by targeting at various oncoproteins for ubiquitin‐mediated degradation. However, the clinical significance and the involving regulatory mechanisms of FBXW7 manipulation of NSCLC regeneration and therapy response are not clear.

Materials and Methods

Immunohistochemical staining and qRT‐PCR were applied to detect FBXW7 and Snai1 expression in 100 samples of NSCLC and matched tumour‐adjacent tissues. FBXW7 manipulation of cancer biological functions were studied by using MTT assay, immunoblotting, flow cytometry, transwells, wound healing assay, and sphere‐formation assays. Immunofluorescence and co‐immunoprecipitation were used to analyse the possible interaction between Snai1 and FBXW7.

Results

We detected the decreased FBXW7 expression in majority of the NSCLC tissues, and lower FBXW7 level was correlated with advanced TNM stage. Furthermore, those patients with decreased FBXW7 expression tend to have both poorer 5‐year survival outcomes, and shorter disease‐free survival, comparing to those with higher FBXW7 levels. Functionally, we found that FBXW7 enforcement suppressed NSCLC progression by inducing cell growth arrest, increasing chemo‐sensitivity and inhibiting Epithelial‐mesenchymal Transition (EMT) progress. Results further showed that FBXW7 could interact with Snai1 directly to degrade its expression through ubiquitylating alternation in NSCLC, which could be partially abrogated by restoring Snai1 expression.

Conclusions

FBXW7 conduction of tumour suppression was partly through degrading Snai1 directly for ubiquitylating regulation in NSCLC

     

Utility of thiol-cross-linked fluorescent dye labeled terminators for DNA sequencing

Dipivaloyl-5-carboxyfluorescein N-hydroxysuccinimidyl ester 1 and 5-propargylamino-2',3'-dideoxyuridine triphosphate 5 were modified with maleimide, haloacetamide, and sulfhydryl reactive functional groups to participate in cross-conjugation reactions via sulfide bonds to generate fluorescently labeled, thioether cross-conjugated terminators 10 and 11. Their DNA sequencing potential was compared with an amide cross-conjugated terminator 13, synthesized by directly coupling 5-carboxyfluorescein NHS ester with 18-ddUTP 9. These terminators (10, 11, and 13) in combination with the Thermo Sequenase II DNA polymerase, in thermal cycle sequencing experiments, revealed that the thioether cross-conjugated terminator 10 and amide cross-conjugated terminator 13 served as good terminating substrates, generating satisfactory single-color gel images and electropherograms, while the other thioether cross-conjugated and maleimide derived one 11 underwent unexpected pH and temperature induced decomposition without showing fluorescent signatures for incorporation.     

FKBP12.6 protects heart from AngII‐induced hypertrophy through inhibiting Ca2+/calmodulin‐mediated signalling pathways in vivo and in vitro

We previously observed that disruption of FK506‐binding protein 12.6 (FKBP12.6) gene resulted in cardiac hypertrophy in male mice. Studies showed that overexpression of FKBP12.6 attenuated thoracic aortic constriction (TAC)‐induced cardiac hypertrophy in mice, whereas the adenovirus‐mediated overexpression of FKBP12.6 induced hypertrophy and apoptosis in cultured neonatal cardiomyocytes, indicating that the role of FKBP12.6 in cardiac hypertrophy is still controversial. In this study, we aimed to investigate the roles and mechanisms of FKBP12.6 in angiotensin II (AngII)‐induced cardiac hypertrophy using various transgenic mouse models in vivo and in vitro. FKBP12.6 knockout (FKBP12.6^?/?) mice and cardiac‐specific FKBP12.6 overexpressing (FKBP12.6 TG) mice were infused with AngII (1500 ng/kg/min) for 14 days subcutaneously by implantation of an osmotic mini‐pump. The results showed that FKBP12.6 deficiency aggravated AngII‐induced cardiac hypertrophy, while cardiac‐specific overexpression of FKBP12.6 prevented hearts from the hypertrophic response to AngII stimulation in mice. Consistent with the results in vivo, overexpression of FKBP12.6 in H9c2 cells significantly repressed the AngII‐induced cardiomyocyte hypertrophy, seen as reductions in the cell sizes and the expressions of hypertrophic genes. Furthermore, we demonstrated that the protection of FKBP12.6 on AngII‐induced cardiac hypertrophy was involved in reducing the concentration of intracellular Ca²⁺ ([Ca²⁺]i), in which the protein significantly inhibited the key Ca²⁺/calmodulin‐dependent signalling pathways such as calcineurin/cardiac form of nuclear factor of activated T cells 4 (NFATc4), calmodulin kinaseII (CaMKII)/MEF‐2, AKT/Glycogen synthase kinase 3β (GSK3β)/NFATc4 and AKT/mTOR signalling pathways. Our study demonstrated that FKBP12.6 protects heart from AngII‐induced cardiac hypertrophy through inhibiting Ca²⁺/calmodulin‐mediated signalling pathways.     

基于微量筛选模型的48种中草药提取物乙酰胆碱酯酶抑制活性筛选及评价

采用微量筛选模型考察48种中药提取物的乙酰胆碱酯酶抑制活性。采用不同极性溶剂对中药材进行提取,采用微量筛选模型对不同浓度提取物的乙酰胆碱酯酶抑制活性进行考察,并采用Origin8.0计算其IC50值。结果表明,几种中药材的不同极性溶剂(水、80%乙醇、乙酸乙酯、石油醚)提取物有不同程度的乙酰胆碱酯酶抑制活性。其中黄柏、元胡的80%乙醇提取物,丹参的乙酸乙酯提取物的抑制率较高。当上述提取物在实验体系中的终浓度为76.92 mg/L时,抑制率分别为66.72±0.02%、52.67±0.04%、46.84±0.03%,其IC50值分别为295.12、229.09、1202.26 mg/L。本研究结果为从中草药中快速筛选乙酰胆碱酯酶抑制剂提供了方法和数据支持。     

有机物和重金属复合污染水体的修复植物筛选及修复性能

通过植物的采集、培育和选种,获得了海芋、合果芋、蜘蛛兰和密穗砖子苗等4种同时具备去碳、脱氮、除磷和积累重金属的高效修复植物,并对这些植物修复污染水体的性能进行了研究.结果表明,这4种植物均能有效地处理有机物和重金属复合污染水体.鲜重55-60g的植物,处理10LBOD₅、COD_Cr、TP、TN、Cu²⁺和Cr⁶⁺浓度分别为140、280、6,8、40、10和10mg·L^-1的模拟水样14d后,上述指标的去除率分别高达80%、72%、64%、53%、75%和68%以上,植物的促进作用分别为32%、27%、27%、28%、37%和19%以上.处理后水样的pH和DO分别为6.63～7.63和3.02～3.84mg·L^-1.     

中药地黄饮子对小鼠抗体激发水平的影响

目的:探讨地黄饮子对小鼠抗体激发水平的影响。方法:将40只经卵核蛋白免疫过的小鼠随机分A、B两组,分别灌服地黄饮子和葡萄糖,1次/d,每次0.5mL只,连续7d后,加强免疫,再经7d,用ELISA法检测血清中相应抗体生成水平。结果:与葡萄糖组比较,地黄饮子组小鼠抗体水平升高,差异有显著性意义(P<0.05)。结论:地黄饮子有可能促进小鼠抗体激发水平和免疫水平的提高。     

放射损伤、烧伤与放烧复合伤血清成份对心肌细胞钙离子通道活动的影响

本实验研究了放射损伤、烧伤与放烧复合伤后血清成份对培养心肌细胞Ｌ－型钙离子通道活动的影响,结果表明：伤后血清对上述通道均有激活作用,从而改变细胞内钙离子水平,此可能为伤后心脏功能抑制的一个重要机理。在作用强度上,复合伤血清重于单一伤、烧伤重于放射损伤,这是导致不同伤后血清对心功能抑制程度不一的重要因素。对伤后血清成分作用的进一步研究表明：伤后血清大分子的作用不明显,主要是血清低分子与血清脂质起作用。其中,放烧复合伤血清低分子不仅使通道开放增加,还使膜片噪声增加,提示其作用包括改变其Ｌ－型钙离子通道活动与改变膜的物理特性二个方面,它们共同导致细胞的功能变化;血清脂质对钙通道的作用可被ＳＯＤ所抑制,表明其作用与氧自由基反应有关。至于伤后血清低分子与血清脂质中的具体毒性成分以及它们对Ｌ－型钙离子通道影响的调控机制,有待于进一步研究     

First-principles study of the structural transformation, electronic structure, and optical properties of crystalline 2,6-diamino-3,5-dinitropyrazine-1-oxide under high pressure

Periodic first-principles calculations have been performed to study the effect of high pressure on the geometric, electronic, and absorption properties of 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) under hydrostatic pressures of 0–50 GPa. Obvious irregular changes in lattice constants, unit-cell angles, bond lengths, bond angles, and band gaps showed that crystalline LLM-105 undergoes four structural transformations at 8, 17, 25, and 42 GPa, respectively. The intramolecular H-bonds were strong at pressures of 0–41 GPa but weakened in the range 42–50 GPa. The lengths of the intermolecular H-bonds (<1.47 Å) indicated that these H-bonds have covalent character and tend to induce the formation of a new twelve-membered ring. Analysis of the DOS showed that the interactions between electrons, especially the valence electrons, strengthen under the influence of pressure. The p states play a very important role in chemical reactions of LLM-105. The absorption spectrum of LLM-105 displayed more bands—as well as stronger bands—in the fundamental absorption region when the pressure was high rather than low. A new absorption peak due to O–H stretching appeared at 18.3 eV above 40 GPa, indicating that covalent O–H bonds and a new twelve-membered ring are present in LLM-105.     

The role of gut microbiota in the gut-brain axis: current challenges and perspectives

Brain and the gastrointestinal (GI) tract are intimately connected to form a bidirectional neurohumoral communication system. The communication between gut and brain, knows as the gut-brain axis, is so well established that the functional status of gut is always related to the condition of brain. The researches on the gut-brain axis were traditionally focused on the psychological status affecting the function of the GI tract. However, recent evidences showed that gut microbiota communicates with the brain via the gut-brain axis to modulate brain development and behavioral phenotypes. These recent fi ndings on the new role of gut microbiota in the gut-brain axis implicate that gut microbiota could associate with brain functions as well as neurological diseases via the gut-brain axis. To elucidate the role of gut microbiota in the gut-brain axis, precise identification of the composition of microbes constituting gut microbiota is an essential step. However, identifi cation of microbes constituting gut microbiota has been the main technological challenge currently due to massive amount of intestinal microbes and the diffi culties in culture of gut microbes. Current methods for identifi cation of microbes constituting gut microbiota are dependent on omics analysis methods by using advanced high tech equipment. Here, we review the association of gut microbiota with the gut-brain axis, including the pros and cons of the current high throughput methods for identifi cation of microbes constituting gut microbiota to elucidate the role of gut microbiota in the gut-brain axis.