The endless tale of non-homologous end-joining

DNA double-strand breaks （DSBs） are introduced in cells by ionizing radiation and reactive oxygen species. In addition, they are commonly generated during V（D）J recombination, an essential aspect of the developing immune system. Failure to effectively repair these DSBs can result in chromosome breakage, cell death, onset of cancer, and defects in the immune system of higher vertebrates. Fortunately, all mammalian cells possess two enzymatic pathways that mediate the repair of DSBs： homologous recombination and non-homologous end-joining （NHEJ）. The NHEJ process utilizes enzymes that capture both ends of the broken DNA molecule, bring them together in a synaptic DNA-protein complex, and finally repair the DNA break. In this review, all the known enzymes that play a role in the NHEJ process are discussed and a working model for the co-operation of these enzymes during DSB repair is presented.

Gender and metabolic differences of gallstone diseases

AIM： To investigate the risk factors for gallstone disease in the general population of Chengdu, China. METHODS： This study was conducted at the West China Hospital. Subjects who received a physical examination at this hospital between January and December 2007 were included. Body mass index, blood pressure, fasting plasma glucose, serum lipid and lipoproteins concentrations were analyzed. Gallstone disease was diagnosed by ultrasound or on the basis of a history of cholecystectomy because of gallstone disease. Unconditional logistic regression analysis was used to investigate the risk factors for gallstone disease, and the Chi-square test was used to analyze differences in the incidence of metabolic disorders between subjects with and without gallstone disease. RESULTS： A total of 3573 people were included, 10.7% （384/3573） of whom had gallstone diseases. Multiple logistic regression analysis indicated that the incidence of gallstone disease in subjects aged 40-64 or ≥65 years was significantly different from that in those aged 18-39 years （P 〈 0.05）; the incidence was higher in women than in men （P 〈 0.05）. In men,a high level of fasting plasma glucose was obvious in gallstone disease （P 〈 0.05）, and in women, hypertriglyceridemia or obesity were significant in gallstone disease （P 〈 0.05）. CONCLUSION： We assume that age and sex are profoundly associated with the incidence of gallstone disease; the metabolic risk factors for gallstone disease were different between men and women.

Potential of kynurenine metabolites in drug development against neurodegenerative diseases

Reactive oxygen species(ROS)and kynurenines:Kynurenines represent a relatively heterogenous group of tryptophan metabolites(Figure 1 A).The amino acid tryptophan is metabolized in the humans by the kynurenine or serotonin pathway.For a long time,the kynurenine pathway was assumed primarily to constitute the source for nicotinamide-adenine dinucleotide phosphate,one of the most utilized redox active enzyme cofactors.

Functional analysis of helicase and three tandem HRDC domains of RecQ in Deinococcus radiodurans

RecQ is a highly conserved helicase necessary for maintaining genome stability in all organisms. Genome comparison showed that a homologue of RecQ in Deinococcus radiodurans designated as DR1289 is a member of RecQ family with unusual domain arrangement: a helicase domain, an RecQ C-terminal domain, and surprisingly three HRDC domain repeats, whose func-tion, however, remains obscure currently. Using an insertion deletion, we discovered that the DRRecQ mutation causes an increase in gamma radiation, hydroxyurea and mitomycine C and UV sensitivity. Using the shuttle plasmid pRADK, we complemented various domains of the D. radiodurans RecQ (DRRecQ) to the mutant in vivo. Results suggested that both the helicase and helicase-and-RNase-D-C-terminal (HRDC) domains are essential for complementing several phenotypes. The complementation and biochemical function of DRRecQ variants with different domains truncated in vitro suggested that both the helicase and three HRDC domains are necessary for RecQ functions in D. radiodurans, while three HRDC domains have a synergistic effect on the whole function. Our finding leads to the hypothesis that the RecF recombination pathway is likely a primary path of double strand break repair in this well-known radioresistant organism.

A need for stratification of metastasis samples according to secondary site in gene expression studies

Comparisons of gene expression profiles between primary tumors and metastasis have revealed genes that are implicated in metastasis formation.However,gene expression studies conducted on metastasis samples from the same primary site usually do not discriminate between different secondary sites.Although the change in the expression of number of genes is expected to be common to metastasis from the same primary but different secondary sites,herein the data that point to substantial differences are presented.Furthermore,the reciprocal communication between metastatic and host cells that is influencing these differences is outlined to emphasize the need for stratification of metastasis samples in gene expression studies.

A Genetic Epidemiological Study on Esophageal Cancer and Carcinoma of the Gastric Cardia in Cixian County of Hebei Province

OBJECTIVE To investigate the role of family aggregation and genetic factors of esophageal cancer （EC）, including carcinoma of gastric cardia （CGC）, in Cixian county, and to calculate the segregation ratio and heritability of first-degree relatives （FDR） in EC cases.METHODS A case control study was conducted, and each of 285 esophageal cancer cases and FDR＇s case history and family medical history of EC in 1415 controls was carried by home visits to compare the incidence of EC in the crowds. The family aggregation of EC was found by X2 test for goodness of fit test according to binomial distribution. Li-Mantel-Gart method was used to calculate the segregation ratio and Falconer method was employed to compute the heritability （h2）.RESULTS The incidence rate of the FDR in the index case of EC （12.80%） was higher than that in the controls （7.52%）. There were significant differences between the 2 groups （X2= 44.34, P = 0.000）. The distribution of EC in the family did not agree with the binomial distribution, which presented a conspicuous familial aggregation （X2= 288.19, P 〈 0.0001）. The heritability of EC was （29.67 ±4.32）%, and segregation ratio was 0.1814 （95%CI = 0.1574-0.2054）, which is lower than 0.25, and can be regarded as a disease of multi-factorial inheritance.CONCLUSION The occurrence of EC in the Cixian County is the outcome of the mutual effect of genetic and environmental factors. The family history of upper gastrointestinal cancers increases the risk of EC in late generations.

Low Prevalence of Carbapenem Resistance in Clinical Isolates of Extended Spectrum Beta Lactamase (ESBL) Producing <i>Escherichia coli</i>in North Central, Nigeria

Extended Spectrum Beta Lactamase (ESBL) producing Escherichia coli is a global cause of life threatening infections. We determined the presence of ESBL and carbapenemase production in clinical isolates of E. coli and their antibiotic susceptibility. Clinical isolates of community and hospital acquired E. coli from 220 patients seen at a tertiary hospital were evaluated. Antibiotic susceptibility testing was by the modified Kirby-Bauer protocol while ESBL production was determined by the Double Disk Synergy Test (DDST). Carbapenem resistance was confirmed by the Modified Hodge Test. Of the 220 isolates, 122 (55.5%) were from females;41 (18.6%) were ESBL positive. About 90% of the ESBL producing isolates were resistant to nine of the 15 antimicrobial agents tested. However, only one (2.4%) of the 41 ESBL producing isolates exhibited carbapenem resistance. The ESBL negative isolates were susceptible to Meropenem (100%), Cefepime (97.8%), Ceftriaxone (96.6%) and Cefotaxime (96.6%). All the ESBL producing isolates harbored detectable plasmids with sizes ranging from 2322 to 23,130 base pairs. Our findings show that although multidrug resistant ESBL producing E. coli are prevalent in both the hospital and the community in this environment, carbapenem resistance is still low. We recommend that institutions develop guidelines for the early phenotypic detection of ESBLs and carbapenem resistance.

Effect of Silica Nanoparticles on Cultured Central Nervous System Cells

Nanotechnology is developing rapidly and the production of novel man-made nanoparticles is increasing. However, the effects of these particles on human health are unevaluated. Depending on particle size and the surface properties, nanoparticles may have the potential to affect human health. In recent studies, several silica nanoparticles (<100 nm) were shown to be penetrating into the brain. Thus, it is important to understand the influence of these nanoparticles on the central nervous system. In this study, we investigated the toxicological influence of nanoparticles on cortical cultured neurons isolated from embryonic day 18 Wister rats. Cortical cultured neurons at 21 days in vitro (DIV) were treated with 30 nm silica nanoparticles for 1 hr. Many neurons were damaged immediately more than at 0.01 mg/ml concentration of silica. Cell damage was also assessed using the lactate dehydrogenase (LDH) assay and the reactive oxygen species (ROS) assay. We revealed that the Neuro-toxicological mechanisms were due to membrane permeability. It was suggested that cell membrane permeability was enhanced because of ROS generation. Given these results, it will be important to determine the effect of nano-silica particles in vivo and identify the extent of neuronal damage.

Additive Effects of Water-Soluble Propolis(Greit 120)and Human Interferon Alfa(HuIFN-αN3)against Influenza Viruses in Vitro

Influenza virus affects the respiratory tract in humans causing a range of distinct manifestations including fever, nasal secretions, cough, headaches, muscle pain and pneumonia, which could become violent and severe. It was found that influenza A viruses remain resistant to amantadine and rimantadin with high level of oseltamvir resistance. Therefore, there is a need for constant improvement of drugs active against resistant influenza viruses. Propolis has anti-influenza activity both in vitro and in vivo. Human leukocyte interferon （HuIFN-αN3） is a multi-subtype protein that displays an antiviral activity against influenza virus. In this study we elucidated the anti-influenza activity of the mixes of water-soluble propolis （WSP） （Greit 120） and HuIFN-αN3 at different ratios. Greit 120 polyphenols, total phenol acids and bioflavonoid were characterized by HPLC-UV-ESI-MS504971 and HuIFN-αN3 by reverse-phase high-performance liquid chromatography （RP-HPLC）. Influenza A and B viruses were separately added to the LLC-MK2 cells treated with WSP （Greit 120） and HuIFN-αN3 alone or in proportions 1：1, 1：2 and 2：1. Plates were incubated and cytopathic effect was determined. The best results （ID50） were obtained with the mix of 10% WSP and HuIFN-αN3 in proportion 1：2, showing ID50 at 12 ± 0.2 μg/mL and 19 ± 0.6 μg/mL for influenza A and B viruses, respectively. When comparing anti-influenza activity of WSP （Greit 120）/HuIFN-αN3 with that of ribavirin, it was found that 1：2 was the optimal ratio for WSP （Greit 120）/HuIFN-αN3 （0.5 and 0.6 for influenza A and B, respectively）. This new formulation of WSP （Greit 120） and HuIFN-αN3, showing better anti-Influenza activity, will definitely improve its application in flu infections.

E2FBP1 antagonizes the p16^(INK4A)-Rb tumor suppressor machinery for growth suppression and cellular senescence by regulating promyelocytic leukemia protein stability

Cellular senescence is an irreversible cell cycle arrest triggered by the activation of oncogenes or mitogenic signaling as well as the enforced expression of tumor suppressors such as p53, p16INK4A and promyelocytic leukemia protein （PML） in normal cells. E2F-binding protein 1 （E2FBP1）, a transcription regulator for E2F, induces PML reduction and suppresses the formation of PML-nuclear bodies, whereas the down-regulation of E2FBP1 provokes the PML-dependent premature senescence in human normal fibroblasts. Here we report that the depletion of E2FBP1 induces the accumulation of PML through the Ras-dependent activation of MAP kinase signaling. The cellular levels of p16INK4A and p53 are elevated during premature senescence induced by depletion of E2FBP1, and the depletion of p16INK4A, but not p53 rescued senescent cells from growth arrest. Therefore, the premature senescence induced by E2FBP1 depletion is achieved through the pl6INK4A-Rb pathway. Similar to human normal fibroblasts, the growth inhibition induced by E2FBP1 depletion is also observed in human tumor cells with intact p16INK4A and Rb. These results suggest that E2FBP1 functions as a critical antagonist to the pI6INK4A-Rb tumor suppressor machinery by regulating PML stability.

The first cavefish in the Dinaric Karst?Cave colonization made possible by phenotypic plasticity in Telestes karsticus

Cave animals are an excellent model system for studying adaptive evolution.At present,however,little is known about the mechanisms that enable surface colonizers to survive in the challenging environment of caves.One possibility is that these species have the necessary genetic background to respond with plastic changes to the pressures of underground habitats.To gain insight into this process,we conducted a comparative study with the fish species Telestes karsticus,which occurs in a hydrological system consisting of an interconnected stream and a cave.Results showed that T.karsticus resided year-round and spawned in Sušik cave,making it the first known cavefish in the Dinaric Karst.Cave and surface populations differed in morphological and physiological characteristics,as well as in patterns of gene expression without any evidence of genetic divergence.To test whether observed trait differences were plastic or genetic,we placed adult fish from both populations under light/dark or constant dark conditions.Common laboratory conditions erased all morphometric differences between the two morphs,suggesting phenotypic plasticity is driving the divergence of shape and size in wild fish.Lighter pigmentation and increased fat deposition exhibited by cave individuals were also observed in surface fish kept in the dark in the laboratory.Our study also revealed that specialized cave traits were not solely attributed to developmental plasticity,but also arose from adult responses,including acclimatization.Thus,we conclude that T.karsticus can adapt to cave conditions,with phenotypic plasticity playing an important role in the process of cave colonization.

Cell polarity protein Par3 complexes with DNA-PK via Ku70 and regulates DNA double-strand break repair

The partitioning-defective 3 （Par3）, a key component in the conserved Par3/Par6/aPKC complex, plays fundamental roles in cell polarity. Herein we report the identification of Ku70 and Ku80 as novel Par3-interacting proteins through an in vitro binding assay followed by liquid chromatography-tandem mass spectrometry. Ku70/Ku80 proteins are two key regulatory subunits of the DNA-dependent protein kinase （DNA-PK）, which plays an essential role in repairing double-strand DNA breaks （DSBs）. We determined that the nuclear association of Par3 with Ku70/Ku80 was enhanced by γ-irradiation （IR）, a potent DSB inducer. Furthermore, DNA-PKcs, the catalytic subunit of DNA-PK, interacted with the Par3/Ku70/Ku80 complex in response to IR. Par3 over-expression or knockdown was capable of up- or downregulating DNA-PK activity, respectively. Moreover, the Par3 knockdown cells were found to be defective in random plasmid integration, defective in DSB repair following IR, and radiosensitive, phenotypes similar to that of Ku70 knockdown cells. These findings identify Par3 as a novel component of the DNA-PK complex and implicate an unexpected link of cell polarity to DSB repair.

Cell polarity protein Par3 complexes with DNA-PK via Ku70 and regulates DNA double-strand break repair

The author affiliations were mixed up in the previous published version. The third fund number of National NaturalScience Foundation of China in the Acknowledgments was wrong, it should be "30270335". The Shanghai MunicipalCouncil for Science and Technology (No.06DZ22032) was missed in the Acknowledgments. There are some labelingand production errors in Figure 2A, Figure 3B and 3C, Figure 5C, Figure 6B and 6E, Figure 7B and 7D. In Figure 2A,left panel "A431" should be "Par3". In Figure 3B and 3C, "anti-Par3CT" should be "anti-Par3LCT", "GST-Par3CT"should be "GST-Par3LCT". In Figure 5C, the second arrow indicating "Lamin B" should be "[3-tubulin". In Figure 6Bright panel, the molecular weight for ?-actin should be "43" instead of"200". In Figure 6E, "Par3" should be "Par3i". Themolecular weight for the DNA-PKcs panel should be the same as the p-DNA-PKcs. In Figure 7B, the time point "240"in the left panel should be "120"; in the right panel of Figure 7B, the title for the y axis should be "DNA released (%)".In Figure 7D, the title for the y axis should be "Survival (%)", and the scale for the y axis should be "100, 10 and 1". These corrections do not affect the conclusions of the study. We apologize for any inconvenience this may havecaused.

Highlights of the 2nd International Symposium on Tribbles and Diseases: tribbles tremble in therapeutics for immunity, metabolism, fundamental cell biology and cancer

The Tribbles(TRIB) family of pseudokinase proteins has been shown to play key roles in cell cycle, metabolic diseases, chronic inflammatory disease, and cancer development. A better understanding of the mechanisms of TRIB pseudokinases could provide new insights for disease development and help promote TRIB proteins as novel therapeutic targets for drug discovery. At the 2 nd International Symposium on Tribbles and Diseases held on May 7–9, 2018 in Beijing, China, a group of leading Tribbles scientists reported their findings and ongoing studies about the effects of the different TRIB proteins in the areas of immunity, metabolism, fundamental cell biology and cancer. Here, we summarize important and insightful overviews from 4 keynote lectures, 13 plenary lectures and 8 short talks that took place during this meeting. These findings may offer new insights for the understanding of the roles of TRIB pseudokinases in the development of various diseases.

Mammalian cell cultures as models for Mycobacterium tuberculosis-human immunodeficiency virus(HIV) interaction studies:A review

Mycobacterium tuberculosis(MTB) and human immunodeficiency virus(HIV) co-infections have remained a major public health concern worldwide,particularly in Southern Africa.Yet our understanding of the molecular interactions between the pathogens has remained poor,primarily due to lack of suitable preclinical models for such studies.We reviewed the use,this far,of mammalian cell culture models in HIV-MTB interaction studies.Studies have described the use of primary human cell cultures,including monocyte-derived macrophage(MDM) fractions of peripheral blood mononuclear cell(PBMC),alveolar macrophages(AM),cell lines such as the monocyte-derived macrophage cell line(U937),T lymphocyte cell lines(CEMx174,ESAT-6-specific CD4+ T-cells) and an alveolar epithelial cell line(A549) and special models such as stem cells,three dimensional(3D) or organoid cell models [including a blood-brain barrier(BBB) cell model] in HIV-MTB interaction studies.The use of cell cultures from other mammals,including:mouse cell lines [macrophage cell lines RAW 264.7 and J774.2,fibroblast cell lines(NIH 3T3,C3 H clones),embryonic fibroblast cell lines and T-lymphoma cell lines(S1A.TB,TIMI.4 and R1.1)]; rat(T cells:Rat2,RGE,XC and HH16,and alveolar cells:NR8383) and primary guinea pigs derived AMs,in HIV-MTB studies is also described.Given the spectrum of the models available,cell cultures offer great potential for host-HIV-MTB interactions studies.

Higher IL-8 Response to <i>Mycobacterium tuberculosis</i>Antigens in Women above 40 Years

Objective: Circulating levels of sex hormones vary with age. Moreover, there is emerging evidence supporting that sex hormones have an influence on the immune response of women. Here, we investigated age-associated levels of sex hormones and Mycobacterium tuberculosis (Mtb) specific cytokines response in women. Design: Using immunoassay methods, we have measured and compared secretion levels of E2, P4 and Mtb specific secretion of 11 cytokines including Granulocyte-macrophage colony-stimulating factor (GM-CSF), Interferon gamma (IFN-γ), Interleukin 1 beta (IL-1β), IL-10, IL-12 (p70), IL-2, IL-4, IL-5, IL-6, IL-8, and Tumor necrosis factor (TNF-α) in forty-two (42) HIV-negative females. Results: Estradiol (E2) and progesterone (P4) levels were significantly higher in younger women irrespective of their LTB status (p < [0.0001 - 0.05]). Mtb IL-8 specific response was significantly higher in women above 40 years old than in women under 40 years old. Conclusion: In premenopausal women, there is an increase in the pro-inflammatory cytokine IL-8 secretion in response to Mtb-antigen. This observation suggests an underlying link between the pro-inflammatory cytokine and age associated hormonal changes, which may have implications on the course of tuberculosis infection women.

The COP9 Signalosome Controls Adipocyte Differentiation by Regulating CHOP Protein Stability

Obesity is a serious health problem of our time. Dysfunction of adipogenesis, the differentiation of adipocytes, is a hallmark of obesity. Therefore here we investigate the role of the COP9 signalosome and of CHOP in the differentiation of LiSa-2 preadipocytes.

Dominance of transposable element‑related satDNAs results in great complexity of“satDNA library”and invokes the extension towards“repetitive DNA library”

Research on bivalves is fast-growing,including genome-wide analyses and genome sequencing.Several characteristics qualify oysters as a valuable model to explore repetitive DNA sequences and their genome organization.Here we char-acterize the satellitomes of five species in the family Ostreidae(Crassostrea angulata,C.virginica,C.hongkongensis,C.ariakensis,Ostrea edulis),revealing a substantial number of satellite DNAs(satDNAs)per genome(ranging between 33 and 61)and peculiarities in the composition of their satellitomes.Numerous satDNAs were either associated to or derived from transposable elements,displaying a scarcity of transposable element-unrelated satDNAs in these genomes.Due to the non-conventional satellitome constitution and dominance of Helitron-associated satDNAs,comparative satellitomics demanded more in-depth analyses than standardly employed.Comparative analyses(including C.gigas,the first bivalve species with a defined satellitome)revealed that 13 satDNAs occur in all six oyster genomes,with Cg170/HindIII satDNA being the most abundant in all of them.Evaluating the“satDNA library model”highlighted the necessity to adjust this term when studying tandem repeat evolution in organisms with such satellitomes.When repetitive sequences with potential variation in the organizational form and repeat-type affiliation are examined across related species,the introduction of the terms“TE library”and“repetitive DNA library”becomes essential.

Optimisation of Adventitious Shoot Regeneration and Agrobacterium-mediated Transformation in Canna × generalis(Canna Lily)

Canna being ornamental plants has a significant role in agriculture, medical, economy and food industry. Canna has a limited vase life due to the rapid loss of moisture from its perianth. For improving its market value, cuticularisation of the perianth can be achieved by the expression of a heterologous cutin producing gene, using the tissue culture and transformation protocol developed in this study. Efficient, rapid and direct adventitious shoot regeneration was successfully established in Canna × generalis using recalcitrant rhizome explants. The explants were cultured on MS medium supplemented with 6-benzylaminopurine(6-BA), thidiazuron(TDZ), and kinetin. Among the four genotypes taken for tissue culture, the ‘Trinacria variegata' was the best responding cultivar. And 2 mg · L^(-1)6-BA or 1.5 mg · L^(-1) TDZ along with 0.1 mg · L^(-1) IAA was optimum for their regeneration. The highest regeneration was achieved in ‘Trinacria variegata'(36%) on 6-BA, 33% on TDZ while kinetin failed to evoke any regenerative responses. Regeneration was enhanced by supplementation of 100 mg · L^(-1) ascorbic acid(AsA), while, 100 mg · L^(-1) of l-cysteine or 100 mg · L^(-1) dithiothreitol(DTT), inhibited regeneration. Shoots were observed to develop 3–5 fibrous roots on MS medium supplemented with 0.5 mg · L^(-1) indole-3-butyric acid(IBA). The plantlets were transplanted into pots and acclimatised in glasshouse with 100%survival. For transformation of Canna, rhizome explants were co-cultivated for 60 min in Agrobacterium suspension. The explants were washed with 500 mg · L^(-1) cefotaxime solution, subjected to 100 mg · L^(-1) kanamycin selection followed by excision of the shoots and culturing them on IBA-supplemented media for root development. Transgene integration in the putative transformants was confirmed by PCR assay and copy number by Southern blot hybridisation analysis.

Insight into the antifungal mechanism of Neosartorya fischeri antifungal protein

Small, cysteine-rich, highly stable antifungal proteins secreted by filamentous Ascomycetes have great po- tential for the development of novel antifungal strate- gies. However, their practical application is still limited due to their not fully clarified mode of action. The aim of this work was to provide a deep insight into the anti-fungal mechanism of Neosartorya fischeri antifungal protein （NFAP）, a novel representative of this protein group. Within a short exposure time to NFAP, reduced cellular metabolism, apoptosis induction, changes in the actin distribution and chitin deposition at the hyphal tip were observed in NFAP-sensitive Aspergillus nidulans. NFAP did show neither a direct membrane disrupting- effect nor uptake by endocytosis. Investigation of A. nidulans signalling mutants revealed that NFAP acti- vates the cAMP/protein kinase A pathway via G-protein signalling which leads to apoptosis and inhibition of polar growth. In contrast, NFAP does not have any in- fluence on the cell wall integrity pathway, but an un- known cell wall integrity pathway-independent mitogen activated protein kinase A-activated target is assumed to be involved in the cell death induction. Taken to- gether, it was concluded that NFAP shows similarities, but also differences in its mode of antifungal action compared to two most investigated NFAP-related pro-teins from Aspergillus giganteus and Penicillium chrysogenum.