Research Progress on Structure-Activity Relationship of 1,8-Naphthalimide DNA Chimeras Against Tumor.

The development of 1,8-naphthalimide derivatives as cell probes, DNA targeting agents, and anti-tumor drugs is one of the research hotspots in the field of medicine. Naphthalimide compounds are a kind of DNA embedder, which can change the topological structure of DNA by embedding in the middle of DNA base pairs, and then affect the recognition and action of topoisomerase on DNA. Aminofide and mitonafide are the first 2 drugs to undergo clinical trials. They have good DNA insertion ability, can embed DNA double-stranded structure, and induce topoisomerase II to cut part of pBR322DNA, but not yet entered the market due to their toxicity. In this paper, the design and structure-activity relationship of mononaphthalimide and bisaphthalimide compounds were studied, and the relationship between the structure of naphthalimide and anti-tumor activity was analyzed and discussed. It was found that a variety of structural modifications were significant in improving anti-tumor activity and reducing toxicity.

Study on the detection of anthrax by ICP-MS based on gold nanoparticle labeling.

BACKGROUND: In recent years, inductively coupled plasma mass spectrometry (ICP-MS) has been widely used in the field of molecular biology because of its unique advantages. Anthrax is a widespread and long-standing infectious disease, which affects and restricts people's work and life seriously. OBJECTIVE: The study goal is to develop a new method for the detection of anthrax. METHODS: A rapid, sensitive and accurate method for the detection of anthrax characteristic DNA was proposed by combing gold nanoparticles (AuNPs) and inductively coupled plasma mass spectrometry. RESULTS: The linear range of this method is 100-2500 pmol/L and the limit of detection of 16.61 pmol/L. CONCLUSION: The proposed method has numerous advantages, including simplicity of operation, high sensitivity, and specificity, which provides a new idea for the detection of anthrax. Importantly, this methodology has good potential for the detection of other biological substances such as bacteria and viruses by changing the modification sequence on the nanoparticle probe.

First Detection of Mukawa Virus in Ixodes persulcatus and Haemaphysalis concinna in China.

Mukawa virus (MKWV), a novel tick-borne virus (TBV) of the genus Phlebovirus of family Phenuiviridae, has been firstly reported in Ixodes persulcatus in Japan. In this study, we made an epidemiological investigation in China to obtain the geographic distribution and genetic features of this virus outside Japan. We screened 1,815 adult ticks (665 I. persulcatus, 336 Dermacentor silvarum, 599 Haemaphysalis longicornis, 170 Rhipicephalus microplus, 45 Haemaphysalis concinna) and 805 wild small mammals collected from eight provinces. The positive rate of 6.77% (45/665, including 18 female and 27 male I. persulcatus) and 2.22% (1/45, 1 male H. concinna) were obtained from I. persulcatus and H. concinna in Heilongjiang province, respectively. No evidence of MKWV infection was found in other three tick species or any of the mammalian species. The virus can infect the Vero cells successfully, indicating the ability of MKWV to replicate in mammalian cells. A phylogenetic tree based on the nucleotide sequences of L, M, and S segments demonstrated that the Japanese MKWV variant, our two MKWV variants, and KURV were clustered with the members of the mosquito/sandfly-borne phleboviruses and distant from other tick-borne phenuiviruses. A phylogenetic analysis based on 895 bp partial L gene sequences (n = 46) showed that all MKWV sequences were separated into three lineages. Our results showed the presence of MKWV in I. persulcatus and H. concinna in northeast of China, highlighting the necessity of epidemiological study in wider regions. Due to the ability of MKWV to replicate in mammalian cells, the potential for zoonosis, and wide distribution of I. persulcatus and H. concinna in China, the important vectors of MKWV, further screening to more tick species, wild animals, domestic animals, and humans raises up practical significance.

Investigating the inotropic effect of pyruvic acid on the isolated rat heart and its underlying mechanism.

Pyruvic acid is important organic chemical intermediates that plays a role in cardiomyocyte pathophysiology and therapy. This study sought to explore the inotropic effects of pyruvic acid on the function of the isolated rat hearts and investigate its underlying mechanism. Pyruvic acid produced a greater negative inotropic effect compared to HCl and sodium pyruvate in a concentration-dependent pattern in the hearts. The role of low dose of pyruvic acid on heart function was regulated by pyruvic acid molecules and high dose pyruvic acid may be influenced by pyruvic acid molecules and pH. Kv channels may be involved in the pyruvic acid-induced negative inotropic effect. Finally, pyruvic acid markedly increased the level of LDH and CK and reduced the level of Ca2+Mg2+-ATPase and Na+K+-ATPase. These results suggest that pyruvic acid may modulate cardiac function at physiological or low doses but can cause damage to cardiomyocytes at high doses.

Formic acid up-regulates vascular tension through nitric oxide-cGMP signaling pathway.

Formic acid is a common organic acid used in many industrial processes. There is a paucity of research on the direct toxicity of formic acid and how it might affect the cardiovascular system. This study aimed to understand the effect of formic acid on vascular tension in an animal model and the underlying mechanism. Results found that the vasodilation induced by formic acid was related to the endothelium. When the dosage of formic acid was 1 mM or 5 mM, the vasodilation of endothelium-intact rings was partially suppressed by l-NAME, NS-2028 and nifedipine, and vasoconstriction caused by CaCl2 was inhibited, and the mRNA levels of eNOS, the activity of NOS (tNOS, iNOS and cNOS) and the level of NO and cGMP were significantly increased. Results also found that eNOS protein expression was significantly enhanced by 5 mM of formic acid. These results suggest formic acid can relax the aortic vessels of rats in a dose-dependent pattern. Further, the mechanism of the formic acid-induced vasodilatation likely involved the NO/cGMP pathway. Finally, the current study has revealed that vasodilation induced by high concentrations of formaldehyde may be the effect of the metabolite formic acid. This study will help further inform the etiologies of formic acid-related angiocardiopathies.

The interaction between the PARP10 protein and the NS1 protein of H5N1 AIV and its effect on virus replication.

BACKGROUND: During the process that AIV infect hosts, the NS1 protein can act on hosts, change corresponding signal pathways, promote the translation of virus proteins and result in virus replication. RESULTS: In our study, we found that PARP domain and Glu-rich region of PARP10 interacted with NS1, and the presence of NS1 could induce PARP10 migrate from cytoplasm to nucleus. NS1 high expression could reduce the endogenous PARP10 expression. Cell cycle analysis showed that with inhibited PARP10 expression, NS1 could induce cell arrest in G2-M stage, and the percentage of cells in G2-M stage rise from the previous 10%-45%, consistent with the cell proliferation result. Plague forming unit measurement showed that inhibited PARP10 expression could help virus replication. CONCLUSIONS: In a word, our results showed that NS1 acts on host cells and PARP10 plays a regulating role in virus replication.

[Cloning, expression and evaluation of Saccharomyces cerevisiae ADH2].

In order to clone and express alcohol dehydrogenase II (ADH2) gene from Saccharomyces cerevisiae in E. coli BL21 (DE3) efficiently, we extracted the total RNA as template and obtained ADH2 gene by RT-PCR and connected ADH2 gene to pTAT plasmids to gain recombinant expression plasmid pTAT-ADH2, then transformed this recombinant expression plasmid pTAT-ADH2 into E. coli BL21 (DE3). The recombinant was induced by IPTG to express ADH2. After purification, ADH2 activity was tested in vitro and toxicologic test was done in mouse. Sequence test showed that the acquired fragments exhibited 90% homology to ADH2 gene sequence from GenBank report. The target gene expressed efficiently and took up to approximant 50% of total protein by SDS-PAGE and band scanning analysis. The purified protein exhibited the identified activity through biochemical test and mouse toxicological test. As a result, the acquired ADH2 gene was highly homology to the published sequence and expressed at a high level in E. coli BL21 (DE3), more importantly, ADH2 proved to have ethanol dehydrogenase activity.

Interaction of influenza virus NS1 protein with growth arrest-specific protein 8.

NS1 protein is the only non-structural protein encoded by the influenza A virus, and it contributes significantly to disease pathogenesis by modulating many virus and host cell processes. A two-hybrid screen for proteins that interact with NS1 from influenza A yielded growth arrest-specific protein 8. Gas8 associated with NS1 in vitro and in vivo. Deletion analysis revealed that the N-terminal 260 amino acids of Gas8 were able to interact with NS1, and neither the RNA-binding domain nor the effector domain of NS1 was sufficient for the NS1 interaction. We also found that actin, myosin, and drebrin interact with Gas8. NS1 and beta-actin proteins could be co-immunoprecipitated from extracts of transfected cells. Furthermore, actin and Gas8 co-localized at the plasma membrane. These results are discussed in relation to the possible functions of Gas8 protein and their relevance in influenza virus release.

[Analysis of PARP10 tissue expression profile, interactive protein and UV stress reaction].

One pair of primers were designed and synthesized based on the cDNA sequence encoding Homo sapiens poly (ADP-ribose) polymerase family, member 10 (PARP10) reported on the GenBank. The cDNA sequence encoding PARP10 was cloned from 293FT cell by RT-PCR. Then the RT-PCR product was cloned into pCMV-Myc and pEGFP-C1 plasmids. The interaction between PARP10 and beta-actin was identified through immuno-precipitation and laser confocal microscopy. Extensive expression of PARP10 in mouse tissues was confirmed by RT-PCR. Besides, Western blotting analysis indicated that cell injury caused by UV treatment could promote the expression of PARP10. The results in this paper would benefit further study of PARP10.

[Effect of influenza virus NS1 protein on host cell].

NS1 is a non-structural protein of the influenza A virus, which could only be expressed when cells are infected. The effect of NS1 protein on host cell is still not clear. To understand the role of NS1 protein in cell infection, recombinant plasmid pCMV-myc-NS1 was constructed, and then transfected into A549 cells. Two-dimensional electrophoresis was employed to analyze proteins regulated by NS1 that could reflect the interaction between influenza virus and host cells at the protein level. The influence of NS1 on cell proliferation and cell cycle was also studied. The result showed that not only could NS1 remarkably affect metabolism, but it could also slow down cell proliferation through blocking cell cycle.