AIMP3 inhibits cell growth and metastasis of lung adenocarcinoma through activating a miR-96-5p-AIMP3-p53 axis

Aminoacyl-tRNA synthetase-interacting multifunctional protein-3 (AIMP3) is a tumour suppressor, however, the roles of AIMP3 in non-small cell lung cancer (NSCLC) are not explored yet. Here, we reported that AIMP3 significantly inhibited the cell growth and metastasis of NSCLC (lung adenocarcinoma) in vitro and in vivo. We have firstly identified that AIMP3 was down-regulated in human NSCLC tissues compared with adjacent normal lung tissues using immunohistochemistry and western blot assays. Overexpression of AIMP3 markedly suppressed the proliferation and migration of cancer cells in a p53-dependent manner. Furthermore, we observed that AIMP3 significantly suppressed tumour growth and metastasis of A549 cells in xenograft nude mice. Mechanically, we identified that AIMP3 was a direct target of miR-96-5p, and we also observed that there was a negative correlation between AIMP3 and miR-96-5p expression in paired NSCLC clinic samples. Ectopic miR-96-5p expression promoted the proliferation and migration of cancer cells in vitro and tumour growth and metastasis in vivo which partially depended on AIMP3. Taken together, our results demonstrated that the axis of miR-96-5p-AIMP3-p53 played an important role in lung adenocarcinoma, which may provide a new strategy for the diagnosis and treatment of NSCLC.     

INO80 participates in the pathogenesis of recurrent miscarriage by epigenetically regulating trophoblast migration and invasion

The INO80 complex, a SWI/SNF family chromatin remodeler, has regulatory effects on ESC self-renewal, somatic cell reprogramming and blastocyst development. However, the role of INO80 in regulating trophoblast cells and recurrent miscarriage (RM) remains elusive. To investigate the in vivo effects of Ino80 in embryo development, we disrupted Ino80 in C57 mice, which resulted in embryonic lethality. Silencing of Ino80 led to decreased survival capacity, migration and invasion of trophoblasts. Furthermore, RNA high-throughput sequencing (RNA-seq) revealed that Ino80 silencing closely resembled the gene expression changes in RM tissues. To investigate the mechanisms for these results, RNA-seq combined with high-throughput sequencing (ChIP-seq) was used in trophoblast cells, and it showed that Ino80 physically occupies promoter regions to affect the expression of invasion-associated genes. Last, Western blotting analyses and immunofluorescence staining revealed that the content of INO80 was reduced in RM patients compared to in healthy controls. This study indicates that INO80 has a specific regulatory effect on the viability, migration and invasion of trophoblast cells. Combined with its regulation of the expression of invasion-associated genes, it has been proposed that epigenetic regulation plays an important role in the occurrence of RM, potentially informing RM therapeutic strategies.     

Lack of Structural Variation but Extensive Length Polymorphisms and Heteroplasmic Length Variations in the Mitochondrial DNA Control Region of Highly Inbred Crested Ibis,Nipponia nippon

The animal mitochondrial DNA (mtDNA) length polymorphism and heteroplasmy are accepted to be universal. Here we report the lack of structural variation but the presence of length polymorphism as well as heteroplasmy in mtDNA control region of an endangered avian species – the Crested Ibis (Nipponia nippon). The complete control region was directly sequenced while the distribution pattern and inheritance of the length variations were examined using both direct sequencing and genotyping of the PCR fragments from captive birds with pedigrees, wild birds and a historical specimen. Our results demonstrated that there was no structural variation in the control region, however, different numbers of short tandem repeats with an identical motif of CA₃CA₂CA₃ at the 3′-end of the control region determined the length polymorphisms among and heteroplasmy within individual birds. There were one to three predominant fragments in every bird; nevertheless multiple minor fragments coexist in all birds. These extremely high polymorphisms were suggested to have derived from the ‘replication slippage’ of a perfect microsatellite evolution following the step-wise mutational model. The patterns of heteroplasmy were found to be shifted between generations and among siblings but rather stable between blood and feather samples. This study provides the first evidence of a very extensive mtDNA length polymorphism and heteroplasmy in the highly inbred Crested Ibis which carries an mtDNA genome lack of structural genetic diversity. The analysis of pedigreed samples also sheds light on the transmission of mtDNA length heteroplasmy in birds following the genetic bottleneck theory. Further research focusing on the generation and transmission of particular mtDNA heteroplasmy patterns in single germ line of Crested Ibis is encouraged by this study.     

Vascular Immunotargeting to Endothelial Determinant ICAM-1 Enables Optimal Partnering of Recombinant scFv-Thrombomodulin Fusion with Endogenous Cofactor

The use of targeted therapeutics to replenish pathologically deficient proteins on the luminal endothelial membrane has the potential to revolutionize emergency and cardiovascular medicine. Untargeted recombinant proteins, like activated protein C (APC) and thrombomodulin (TM), have demonstrated beneficial effects in acute vascular disorders, but have failed to have a major impact on clinical care. We recently reported that TM fused with an scFv antibody fragment to platelet endothelial cell adhesion molecule-1 (PECAM-1) exerts therapeutic effects superior to untargeted TM. PECAM-1 is localized to cell-cell junctions, however, whereas the endothelial protein C receptor (EPCR), the key co-factor of TM/APC, is exposed in the apical membrane. Here we tested whether anchoring TM to the intercellular adhesion molecule (ICAM-1) favors scFv/TM collaboration with EPCR. Indeed: i) endothelial targeting scFv/TM to ICAM-1 provides ∼15-fold greater activation of protein C than its PECAM-targeted counterpart; ii) blocking EPCR reduces protein C activation by scFv/TM anchored to endothelial ICAM-1, but not PECAM-1; and iii) anti-ICAM scFv/TM fusion provides more profound anti-inflammatory effects than anti-PECAM scFv/TM in a mouse model of acute lung injury. These findings, obtained using new translational constructs, emphasize the importance of targeting protein therapeutics to the proper surface determinant, in order to optimize their microenvironment and beneficial effects.     

An ERP Study of the Processing of Common and Decimal Fractions: How Different They Are

This study explored event-related potential (ERP) correlates of common fractions (1/5) and decimal fractions (0.2). Thirteen subjects performed a numerical magnitude matching task under two conditions. In the common fraction condition, a nonsymbolic fraction was asked to be judged whether its magnitude matched the magnitude of a common fraction; in the decimal fraction condition, a nonsymbolic fraction was asked to be matched with a decimal fraction. Behavioral results showed significant main effects of condition and numerical distance, but no significant interaction of condition and numerical distance. Electrophysiological data showed that when nonsymbolic fractions were compared to common fractions, they displayed larger N1 and P3 amplitudes than when they were compared to decimal fractions. This finding suggested that the visual identification for nonsymbolic fractions was different under the two conditions, which was not due to perceptual differences but to task demands. For symbolic fractions, the condition effect was observed in the N1 and P3 components, revealing stimulus-specific visual identification processing. The effect of numerical distance as an index of numerical magnitude representation was observed in the P2, N3 and P3 components under the two conditions. However, the topography of the distance effect was different under the two conditions, suggesting stimulus specific semantic processing of common fractions and decimal fractions.     

The rate of opening and closing of the DNA gate for topoisomerase II

Type II DNA topoisomerases can catalyze the transport of one DNA segment through a transient break in another DNA segment by a complex mechanism of ATP hydrolysis. According to the hydrolysis process of two ATPs, a multi-state model is proposed to investigate the work cycle of DNA topoisomerase II. The rate of the opening and closing of the DNA topoisomerase gate is evaluated by determining the release rate of inorganic phosphates. The calculated results show that, under the condition of the high concentration of ATP, the work cycle of DNA topoisomerase II is about 0.84 s which is in agreement with the experimental data.     

Cytochrome bc1 complex [2Fe-2S] cluster and its interaction with ubiquinone and ubihydroquinone at the Qo site: a double-occupancy Qo site model.

The ubiquinone complement of Rhodobacter capsulatus chromatophore membranes has been characterized by its isooctane solvent extractability and electrochemistry; we find that the main ubiquinone pool (Qpool) amounts to about 80% of the total ubiquinone and has an Em7 value close to 90 mV. To investigate the interactions of ubiquinone with the cyt bc1 complex, we have examined the distinctive EPR line shapes of the [2Fe-2S] cluster of the cyt bc1 complex when the Qpool-cyt bc1 complex interactions are modulated by changing the numbers of Q or QH2 present (by solvent extraction and reconstitution), by the exposure of the [2Fe-2S] to the Qpool in different redox states, by the presence of inhibitors specific for the Qo site (myxothiazol and stigmatellin) and Qi site (antimycin), and by site-specific mutations of side chains of the cyt b polypeptide (mutants F144L and F144G) previously identified as important for Qo site structure. Evidence suggests that the Qo site can accommodate two ubiquinone molecules. One (designated Qos) is bound relatively strongly and is second only to the ubiquinone of the QA site of the reaction center in its resistance to solvent extraction. In this strong interaction, the Qo site binds Q and QH2 with approximately equal affinities. Their bound states are distinguished by their effects on the [2Fe-2S] cluster spectral feature at gx at 1.783 (Q) and gx at 1.777 (QH2); titration of the line-shape change reveals an Em7 value of approximately 95 mV. The other molecule (Qow) is bound more weakly, in the same range as the ubiquinone of the QB site of the reaction center. Again, the affinities of the Q form (gx at 1.800) and QH2 form (gx at 1.777) are nearly equal, and the Em7 value measured is approximately 80 mV. These results are discussed in terms of earlier EPR analyses of the cyt bc1 complexes of other systems. A Qo site double-occupancy model is considered that builds on the previous model based on Qo site mutants [Robertson, D. E., Daldal, F.,& Dutton, P. L. (1990) Biochemistry 29, 11249-11260] and includes the recent suggestion that two of the [2F3-2S] cluster ligands of the R. capsulatus cyt bc1 complex are histidines [Gurbiel, R. J. Ohnishi, T., Robertson, D. E. Daldal, F., & Hoffman, B. M. (1991) Biochemistry 30, 11579-11584]. We speculate that the cyt bc1 complex complexes a full enzymatic turnover without necessary exchange of ubiquinone with the Qpool.