Gotoh. Electronic supplementary material Additional file 1: Figure S1. Cross-streak experiment for detection of bacterial interaction via acyl-HSLs. The two monitor strains used were KG7004 (ΔlasI ΔrhlI) and KG7050 (ΔlasIΔrhlI4 ΔmexB) harboring the lasB promoter-gfp plasmid (pMQG003) were used. Test strains against the monitor strains (center) were cross-streaked on LB agar plates. Following 24 h incubation at30°C, the growth of strains was observed under a stereomicroscope, and then production of GFP by the monitor strains was visualized by excitation of the plates with blue light. (PDF 668 KB) Additional file 2: Figure S2. TLC analysis of 3-oxo-C10-HSL produced by V. anguillarum.

Extracted samples from V. anguillarum H 89 cultures were chromatographed check details on a C-18 RP-TLC plate, developed with methanol/water (70:30, v/v). The spots were visualized 13 by overlaying the TLC plate with C. violaceum VIR07. As AHL standards, Cn-HSL: 14 C6-HSL, C8-HSL and C10-HSL, 3-oxo-Cn-HSL: 3-oxo-C6-HSL, 3-oxo-C8-HSL, 15 3-oxo-C10-HSL and 3-oxo-C12-HSL were used. (PDF 389 KB) Additional file 3: Supplemental information

of Materials, Methods, Figure legend of Figure S1 and S2 and References[1, 45–49]. (PDF 329 KB) References 1. Fuqua C, Greenberg EP: Listening in on bacteria: acyl-homoserine lactone signaling. Nat Rev 2002, 3:685–695.CrossRef 2. Waters CM, Bassler BL: Quorum sensing: cell-to-cell communication in bacteria. Annu Rev Cell Dev Biol 2005, 21:319–346.PubMedCrossRef 3. Duan K, Surcttc MG: Environmental regulation of Pseudomonas aeruginosa PAO1 Las and Rhl quorum-sensing system. J Bacteriol 2007, 189:4827–4836.PubMedCrossRef 4. Schuster M, Lostroh CP, Ogi T, Greenberg EP: Identification, timing, and signal specificity of Pseudomonas

aeruginosa quorum-controlled genes: a transcriptome analysis. Histone demethylase J Bacteriol 2003, 185:2066–2079.PubMedCrossRef 5. Wagner VE, Li LL, Isabella VM, Iglewski BH: Analysis of the hierarchy of quorum-sensing regulation in Pseudomonas aeruginosa. Anal Bioanal Chem 2007, 387:469–479.PubMedCrossRef 6. Bottomley MJ, Muraglia E, Bazzo R, Carfi A: Molecular insights into quorum sensing in the human pathogen Pseudomonas aeruginosa from the structure of the virulence regulator LasR bound to its autoinducer. J Biol Chem 2007, 282:13592–13600.PubMedCrossRef 7. Dubem JF, Diggle SP: Quorum sensing by 2-alkyl-4-quinolones in Pseudomonas aeruginosa and other bacterial species. Mol Biosyst 2008, 4:882–888.CrossRef 8. Pearson JP, Gray KM, Passador L, Tucker KD, Eberhard A, Iglewski BH, Greenberg EP: Structure of the autoinducer required for expression of Pseudomonas aeruginosa virulence genes. Proc Natl Acad Sci USA 1994, 91:197–201.PubMedCrossRef 9. Bredenbruch F, Geffers R, Nimlz M, Buer J, Haussler S: The Pseudomonas aeruginosa quinolone signal (PQS) has an iron-chelating activity. Environ Microbiol 2006, 8:1318–1329.PubMedCrossRef 10.

g. uranium ore immersed in aqueous solutions of proper starting compounds. Anyway, sources Bucladesine research buy of energy as “software” can work creatively only in suitable locations, in analogy to “hardware” in computer calculations (Zagórski 2010a). One can expect similar products of ionizing radiation interaction as with electric discharges and the same main trouble, i.e. production of racemic amino acids, without any enantiomorphic excess. Chemical changes induced in the media by radiation are of prebiotic character but could not alone be responsible for the decisive (as far

we know) character for the formation of life. For instance they could not contribute to the separation of racemic mixtures into separate enantiomorphic species. In spite of no optical activity segregation, one can call ionizing radiation and its cousins in the high energy chemistry family friends to the origins of life chemistry. That field of research is not exhausted yet and many prebiotic or probiotic reactions hopefully will be found with active involvement of ionizing radiation in the formation of different organics. Coming to the second face of ionizing radiation connections to life, are chemical effects connected with modification of the molecules of life. They can be of destructive character but sometimes play a supporting role by positive action

in biological evolution. Omnipresent ionizing radiation was acting on every sort of chemical compounds in the chain of origin of life and evolution of the biosphere, MMP inhibitor from prebiotic compounds, sometimes created with the participation

of ionizing radiation to more or less developed organisms classified as living creatures. The action of radiation can be a direct one on molecules absorbing it, or an indirect one, by products of radiolysis of the medium on dispersed compounds in it and on organisms. Even high LET value radiations of low penetration, like alphas from radon, abundant on early Earth, were of enormous influence, because they were able to penetrate everything exposed to the air, including the first living creatures inhaling the air (Zagórski 2010b). Adenosine triphosphate Whatever the detailed chemical effects, investigated and generalized by principles of radiation chemistry, absorption of ionizing radiation means a supply of energy to the system, participating in the so called “chemical evolution” (no direct analogy to the Darwinian biological evolution). Chemical changes induced in the media by radiation were of prebiotic character but could not alone be responsible for decisive (as far we know) character for the formation of life. For instance, as mentioned before, they could not contribute to the separation of racemic mixtures into separate enantiomorphic species.

FISH-FC approach showed a phylogenetic gap ranging from 22.89% to 37.40% of total bacteria for the four time points. A similar bacterial coverage was reported by Fallani et al using the same method, where the sum of bacterial cells detected were 72.7% ± 24.5% [10] and 74.3% ± 18.9% [45] with a panel of 10 non-overlapping probes.

We acknowledge that the molecular techniques applied in this study do not permit a thorough description of the bacterial population inhabiting the human colon. Future studies would aim to utilize deep sequencing of the 16S rRNA genes so as to delve in depth the bacterial communities populating the human microbiome [46, 47]. Their greater depths of sampling offer the opportunity to explore within the phylogenetic gap and beyond, therefore allowing high-resolution association studies involving the bacterial populations of the human microbiome Copanlisib as “”quantitative traits”". Conclusions In conclusion, we have shown that variations in term of relative abundance in infant fecal microbiota are discernable for bacterial groups between two Asian populations of different geographical locations. The differences in the stool microbiota were partly explained by certain Selleck EPZ5676 lifestyle and clinical factors. These features may confound studies relating to the association of stool microbiota and the predisposition to disease,

and should be an important confounder to take note for comparative studies that enrol large population cohort across different geographical origins. Methods Subject recruitment and study design The SG at risk of atopy cohort (n = 42) is a subgroup selected from the placebo arm (n = 112) of a randomized double-blind placebo controlled clinical trial on the administration of probiotics supplemented cow’s milk-based infant formula for 6 months on the prevention

of eczema and allergic diseases. The placebo group of the study received the same cow’s milk-based infant formula Hydroxychloroquine in vivo without probiotics. This study was conducted at National University of Hospital, Singapore (ClinicalTrials.gov Identifier: NCT00318695) [48]. The Indonesia at risk of atopy cohort (n = 32) was selected from a birth cohort study (n = 66) recruited from expectant mothers who visited Gadjah Mada University Hospital, Yogyakarta. The inclusion criteria for both cohorts were 1) first-degree relative with a history of allergic disorder as confirmed by a doctor’s diagnosis of asthma, allergic rhinitis, or eczema and a positive skin prick test to any of a panel of common dust mite allergens, which are the most important inhalant allergens in our atopic population [49]; 2) gestational age above 35 wk and birth weight above 2 kg; 3) absence of major congenital malformations or major illness at birth; 4) deemed to be in good health based on medical history and physical examination; and 5) the family assessed to be able to complete the trial.

The modification consisted in insertion of the sequence coding for the StrepTag II peptide (WSHPQFEK) in the 5′end of the antibiotic resis-tance gene of the pKD3 plasmid [19] resulting in plasmid pPM71. This plasmid was used as template for in-frame fusing of the StrepTag II sequence to the 3′ end of hupF from pALPF1 plasmid using TAGF31-TAGF32 by a procedure previously described [19]. The resulting pALPF1 derivative

plasmid pALPF382 harbors a hydrogenase gene cluster encoding hupF::StrepTag II (hupF ST ). In order to express hupF ST gene in microaerobically grown cultures of R. leguminosarum in a compatible way with Hup expression from pALPF1 derivatives, a pBBR1MCS derivative plasmid (pPM501) harboring hupF ST was constructed. LOXO-101 concentration To this end we amplified this gene using plasmid pALPF382 as template and FNDE-MANG3 primers.

Amplified fragment was cloned (NdeI-XbaI) in pPM1350 plasmid [19]. This plasmid harbors the P fixN promoter from pALPF1 that is expressed in microaerobic conditions under the control of the FnrN protein. A truncated form of HupFST lacking the C-terminal region (HupFCST) was generated by using plasmid pALPF1 as template for the in-frame deletion of the 25 codons at the 3′ end of hupF gene. The sequence coding for the StrepTagII peptide find more was fused in frame to the corresponding site of hupF using primers FNDE and HUPF-3413 L-Strep. Amplified DNA was cloned in PCR 2.1-TOPO, and the construct was confirmed by sequencing. Then, the DNA region containing the truncated hupF gene

(hupF CST ) was excised with NdeI and XbaI and cloned downstream the P fixN promoter of plasmid pPM1350, resulting in plasmid pPM501C. For this cloning we took advantage of the NdeI site generated with primer FNDE and others the XbaI site from plasmid PCR2.1.-TOPO. Purification of HupF-StrepTag II fusion protein Protein purification was carried out from 3 l of bacterial cultures of R. leguminosarum induced for hydrogenase activity under continuous bubbling with a 1% O2 gas mixture. 40 ml portions of cultures were centrifuged, and cells were resuspended in 5 ml Dixon buffer and assayed for hydrogenase activity as described before. Cell suspensions and extracts used for protein purification were bubbled with argon to avoid damage of hydrogenase from O2 exposure, and centrifuged at 6000 rpm at 4°C for 10 minutes.

Only D11 transformed with pKH12 (the complete 10.6 kb region) was able to grow comparably to FB24 on 0.1X (NA) plates containing 5 mM chromate (Figure 3). The other transformants, in which regions

of the CRD were deleted, were able to grow only at lower levels of chromate (0.5 to 2 mM). In particular, chrA produced a Trichostatin A resistance level of 0.5 mM Cr(VI) regardless of the presence of chrB-Nterm and chrB-Cterm. Expression of chromate resistance genes in strain FB24 under chromate stress Quantitative RT-PCR was employed this website to determine if expression of the chromate resistance genes was inducible by and specific to Cr(VI). Transcription from each of the eight genes of the CRD was induced by increasing concentrations of chromate (Table 1). Five μM chromate was sufficient to detect enhanced expression of each gene. For most genes in the CRD, maximal expression was achieved at 0.1 mM Cr(VI). In the case of chrB-Nterm, Arth_4253, maximum transcript abundance occurred at 5 μM chromate and was maintained up to 20 mM Cr(VI). ChrB-Cterm2, Arth_4249, exhibited low (2-fold) induction at 5, 25 and 50 μM Cr, followed by a sharp increase in transcript levels at 0.1 mM Cr(VI). Specificity of induction of

the CRD genes was assessed with lead, arsenate and hydrogen peroxide, all of which induced little or no expression (Table 2). Table 1 Expression

of CRD genes Amrubicin under various levels of chromate stressa. CRD Gene Basal Expression In 0 mM Cr(VI)b × 102 Relative Fold Differencec Cr(VI)/0 mM Cr(VI)     0.005 0.025 0.05 0.1 5 20 100 chrL 4.20 (0.45) 36.7* (9.3) 95.2 (8.7) 69.8 (12.1) 95.1 (42.9) 63.4 (29.7) 45.1* (14.3) 15.3* (3.5) chrA 6 2.25 (0.36) 8.5* (1.3) 16.2* (3.9) 27.4* (2.5) 42.1 (4.2) 50.7 (14.5) 37.6 (9.8) 22.9 (8.2) chrB-Cterm2 15.6 (4.95) 2.0* (0.3) 2.2* (0.5) 2.5* (0.5) 7.1 (2.6) 6.3 (1.8) 8.0 (3.2) 2.0* (0.8) SCHR 8.50 (2.06) 1.9* (0.5) 4.7* (0.6) 5.1* (0.7) 7.8 (0.7) 6.8 (1.9) 5.1 (1.2) 2.1* (0.9) chrK 21.9 (2.89) 3.7* (0.5) 6.1* (0.7) 7.5 (1.9) 10.1 (1.9) 7.2 (1.6) 6.9 (1.6) 4.4 (1.4) chrB-Nterm 249 (86.4) 8.0 (2.6) 12.5 (4.0) 13.8 (5.6) 18.0 (8.0) 16.9 (7.1) 14.0 (6.5) 4.2 (1.5) chrB-Cterm 0.51 (0.04) 4.3* (0.7) 8.4* (2.1) 16.0* (1.5) 21.3 (2.0) 25.4 (4.4) 30.9 (6.0) 15.3 (5.5) chrJ 1.23 (0.40) 7.2* (1.5) 14.3* (2.8) 19.0* (2.5) 37.0 (15.0) 92.4 (47.2) 47.6 (13.2) 19.2 (6.7) a The basal (0 mM Cr(VI)) transcript levels are given in copy number/ng total RNA.

Mol Genet Genomics 2009, 281:19–33.CrossRefPubMed

15. Lange R, Hengge-Aronis R: Identification of a central regulator of stationary-phase gene expression in Escherichia coli. Mol Microbiol 1991, 5:49–59.CrossRefPubMed 16. Small P, Blankenhorn D, Welty D, Zinser E, Slonczewski JL: Acid and base resistance in Escherichia coli and Shigella flexneri : role of rpoS and growth pH. J Bacteriol 1994, 176:1729–1737.PubMed 17. Hengge-Aronis R, Klein W, Lange R, Rimmele M, Boos W: Trehalose synthesis genes are controlled by the putative sigma factor learn more encoded by rpoS and are involved in stationary-phase thermotolerance in Escherichia coli. J Bacteriol 1991, 173:7918–7924.PubMed 18. Sammartano LJ, Tuveson RW, Davenport R: Control of sensitivity to inactivation by H2O2 and broad-spectrum near-UV radiation by the Escherichia coli katF ( rpoS ) locus. J Bacteriol 1986, 168:13–21.PubMed 19. Atlung T, Nielsen HV, Hansen FG: Characterisation of the allelic variation in the rpoS gene in

thirteen K12 and six other non-pathogenic Escherichia coli strains. Mol Genet Genomics 2002, 266:873–881.CrossRefPubMed 20. Subbarayan PR, Sarkar M: A comparative study of variation in codon 33 of AZD6738 the rpoS gene in Escherichia coli K12 stocks: implications for the synthesis of sigma(S). Mol Genet Genomics 2004, 270:533–538.CrossRefPubMed 21. Waterman SR, Small PL: Characterization of the acid resistance phenotype and rpoS alleles of shiga-like Interleukin-2 receptor toxin-producing Escherichia coli. Infect Immun 1996, 64:2808–2811.PubMed 22. King T, Ishihama A, Kori A, Ferenci T: A regulatory trade-off as

a source of strain variation in the species Escherichia coli. J Bacteriol 2004, 186:5614–5620.CrossRefPubMed 23. Chen G, Patten CL, Schellhorn HE: Positive selection for loss of RpoS function in Escherichia coli. Mutat Res 2004, 554:193–203.PubMed 24. Spira B, Hu X, Ferenci T: Strain variation in ppGpp concentration and RpoS levels in laboratory strains of Escherichia coli K-12. Microbiology 2008, 154:2887–2895.CrossRefPubMed 25. Cummings JH, Pomare EW, Branch WJ, Naylor CP, Macfarlane GT: Short chain fatty acids in human large intestine, portal, hepatic and venous blood. Gut 1987, 28:1221–1227.CrossRefPubMed 26. Rosenthal AZ, Hu M, Gralla JD: Osmolyte-induced transcription: -35 region elements and recognition by sigma38 (rpoS). Mol Microbiol 2006, 59:1052–1061.CrossRefPubMed 27. Rasko DA, Rosovitz MJ, Myers GS, Mongodin EF, Fricke WF, Gajer P, Crabtree J, Sebaihia M, Thomson NR, Chaudhuri R, et al.: The pangenome structure of Escherichia coli: comparative genomic analysis of E. coli commensal and pathogenic isolates. J Bacteriol 2008, 190:6881–6893.CrossRefPubMed 28. Karmali MA: Infection by verocytotoxin-producing Escherichia coli. Clin Microbiol Rev 1989, 2:15–38.PubMed 29.

With his typical sense of humor, David wrote at the end of his paper with Tom: “In advocating the virtues of the oxygen electrode we would not wish to convey the impression they are yet entirely foolproof. They are like the legendary little girl in that when they are good they are very, very good; but, when they are bad they are horrid.” (Delieu and Walker 1972). David linked up with John Humby, the result of which was a long and fruitful

LY2109761 concentration collaboration in marketing apparatus through Hansatech Instruments. In the early 1980s, David had Tom construct an instrument that would measure oxygen in the gas phase, which became the leaf disc electrode (where light response of photosynthesis and maximum quantum yields can be readily analyzed). Polarographic equipment was also further developed to simultaneously

analyze O2 evolution and the fate of energy absorbed by PSII by chlorophyll fluorescence. These instruments stimulated a great deal of new research around the world and led to the establishment of the “gold standard” for the quantum yield of C3 photosynthesis in vivo (Björkman and Demmig LY3023414 price 1987). Two important scientific meetings flowed from these developments. Peter Horton, in reflecting on the truly immense contributions David made to photosynthesis research at Sheffield, recalls an exciting event from the early days of the Hill Laboratory when he convened a symposium with the title, “What Limits Photosynthesis?”, a question which is still largely unanswered in many respects and very pertinent to all the renewed interest in “improving photosynthesis”. David

later organized a Royal Society discussion meeting in London on “New Vistas in Measurement of Photosynthesis” that brought together these and other technical advances for measurement of photosynthesis in vivo (Walker 1989; Walker and Osmond 1989). (See http://​www.​hansatech-instruments.​com/​nostalgia.​htm; Delieu and Walker 1981, 1983; Walker 1987, 1992a, b, 1997, 2003a.) Major books and making science accessible to the public David made major, lasting contributions in his writings about very photosynthesis and its relevance to mankind, not only for scientists, but in forms that were readily accessible and appealing to people of all ages and at all levels of scientific sophistication (Fig. 2). Fig. 2 Illustrations of types of books and the Pub understanding of science by David Walker. Visit: http://​www.​hansatech-instruments.​com/​david_​walker.​htm for free download including (i). Books on photosynthesis: ‘Global Climate Change’, ‘Energy, Plants and Man; Like Clockwork’; ‘C3, C4′. (ii). ‘A Leaf in Time‘; Spanish translation of ‘A Leaf in Time‘; ‘A New Leaf in Time’. (iii.) Technical Manual: ‘The use of the Oxygen Electrode and Fluorescence Probes in simple measurements of Photosynthesis’. (iv). PowerPoint Presentations: ‘Starch Pictures‘; ‘The Z-scheme‘. (v.

These results indicate a potentially significant level of horizontal gene transfer among Acinetobacter species and illustrate an inability to delineate species based on gene content comparison only. These findings suggest that ANI analyses provide results that are compatible with traditional and phylogenetic classifications, whereas K-string and genome fluidity approaches

appear to be too strongly influenced by the effects of horizontal gene transfer to be consistent with previously accepted approaches. Defining species in Acinetobacter on the basis of whole-genome analyses The congruence of the phylogenetic tree and ANI dendogram with each other and with existing Ku-0059436 species definitions provides confidence

that these techniques are fit for purpose in delineating species in the absence of phenotypic data. Furthermore, as Goris et al. suggest, the ANI approach provides a handy numerical cut-off at 95% identity to demarcate species boundaries, which corresponds to the 70% DDH value [10]. When we applied selleck compound this cut-off to our dataset, we were able to classify 37 of the strains into thirteen previously named species. In line with the likely misclassification of strains, we observed that A. nosocomialis NCTC 10304 shares phylogenetic history and exhibits pair-wise ANI values greater than 95% with all 14 sequenced A. baumannii strains, thus confirming it should be designated A. baumannii NCTC 10304. Similar arguments apply for A. calcoaceticus PHEA-2 (new designation A. pittii PHEA-2) and A. sp. ATCC 27244 (A. haemolyticus ATCC 27244). However, the strain NCTC 7422 appears to be distinctive enough to represent new species. While the traditional polyphasic approach to taxonomy demands additional phenotypic characterization before these species can be named, on the basis of the analyses presented here, we isometheptene propose the species name Acinetobacter bruijnii sp. nov. (N. L. gen. masc. n. bruijnii, of Bruijnius, named

after Nicolaas Govert de Bruijn, Dutch mathematician) for strain NCTC 7422 and all future strains that are monophyletic and show ≥ 95% ANI to this strain. It is interesting to note that our results based on core genome and ANI analyses differ from those based on AFLP patterns [56]; notably in the latter A. haemolyticus and A. junii do not cluster together nor does the cluster form a sister branch to the ACB complex; also A. johnsonii does not appear on the same deep-branch as A. lwoffii. This observation suggests that although AFLP is adept at species resolution, it appears to be unsuitable for phylogenetic analysis. Several recent studies report alternative genomic approaches to bacterial taxonomy and species identification.

The broth cultures were grown at their respective temperature of the isolates with shaking at 200 rpm till the cultures reached OD600 of 0.4-0.5. Thereafter, cells were pelleted by centrifugation at 9167 × g for 10 min at 4°C and washed with TE buffer [10 mM Tris–HCl pH 8.0, 1 mM ethylenediaminetetraacetic acid (EDTA)] and pellets were either frozen (-20°C) for storage or used immediately for genomic DNA extraction by using the method of Sambrook & Russell [69]. DNA samples were quantified by running on agarose gel electrophoresis

using 0.8% agarose gel in 1 × tris-boric acid EDTA (TBE) (89 mM tris pH 7.6, 89 mM boric acid, 2 mM EDTA) and visualized by ethidium bromide Temsirolimus (0.5 μg ml-1) staining, to determine DNA size and to assess RNA contamination. PCR Amplification and sequencing Amplifications were performed in 50 μl reaction mixture containing 75 ng of template DNA, 1-unit of i-Taq™ polymerase (NEB, UK), 2 mM MgCl2 (NEB, UK) , 2 μl of 10X PCR buffer, 0.1 mM dNTP (NEB, UK), 100 ng of each forward (8f’:5’-AGAGTTTGATCCTGGCTCAG-3’ [70]), and reverse (1542r’:5′-AAGGAGGTGATCCAGCCGCA-3’

[71]) primers. The amplification was carried out using G-strom thermal cycler (Labtech, UK). Amplification programme consisted of initial cycle of denaturation at 94°C for 5 min, 30 cycles of denaturation at 94°C for 1 min, annealing at 58°C for 1 min, initial extension at 72°C for 1 min 30

sec and final extension at 72°C for 7 min. Amplified products were electrophoresed see more at 5 Vcm-1 through 1.5% agarose gel containing 0.5 μg ml-1 ethidium bromide in 1xTBE electrophoresis buffer with 50 bp DNA Ladder (NEB, UK). The gels were visualized under UV illumination in Gel Documentation system 2000 (Biorad, Hercules CA, USA) and stored as TIFF file format. Sizes of the amplicons were estimated in comparison with 50bp DNA ladder (NEB, UK). Sequencing of 16S rRNA gene and phylogenetic analysis The expected DNA band of 1.5 kb was excised from gel and purified selleck screening library using the gel elution kit (Sigma-Aldrich, USA) as per the manufacturer’s protocol. Sequencing reactions were carried out with a BigDye Terminator cycle sequencing kit (Applied Biosystems, USA), standard universal primer forward (8f’) and reverse (1542r’) primer and sequenced by using ABI Prism 3100 genetic analyzer (Applied Biosystems, USA). The sequences thus obtained were assembled and edited using Clone Manager Version 5 (http://​www.​scied.​com/​pr_​cmbas.​htm). Database search was carried out for similar nucleotide sequences with the BLAST search of Non-reductant (NR) database (http://​blast.​ncbi.​nlm.​nih.​gov/​Blast.​cgi) [72]). Partial length 16S rRNA gene sequences of strains closely related to the isolate were retrieved from NCBI for further analysis.

CagA has been associated with both stimulation

and inhibition of apoptosis [11, 12, 34]. Biliary cells exposed to cagA + H. pylori at a very low inoculum (MOI 1:1) demonstrated increased cell growth, whereas at MOI of 200:1, apoptosis was stimulated [35]. CagA may even directly antagonize the pro-apoptotic effect of VacA, as seen in AGS cells [31]. Apoptosis occurs after a number NVP-BSK805 supplier of cellular events, leading to activation of caspase-3, which is thought to constitute the basic effector of apoptosis. In the present study, both inhibitory and stimulatory genes showed significant differential expression, demonstrating the complexity of the influence of H. pylori on apoptosis: caspase inhibitors HSPA5 and DHCR24 showed similar late down-regulation as heat shock genes HSPA1B, HSPB1, which are also associated with apoptosis stimulation (cluster E, Table 3). On the other hand, TNFAIP3, BIRC2, BIRC3 and SERPINB2,

also associated with apoptosis inhibition, demonstrated early and persistent Torin 1 up-regulation grouped together in cluster A. However, positive regulators of apoptosis PTPRH, TNFRSF12A, IL24, GADD45A, TRIB3, DDIT4, PHLDA4, PP1R15A and SQSTM1 were all up-regulated in similar pattern after 6-12 h (cluster C). MCL1, an anti-apoptotic gene expressed in response to CagA injection [11], demonstrated increasing up-regulation over the course of the study. There were no significant changes in BCL-2 and very Pyruvate dehydrogenase little increase in BAX expression in our study, two important genes that determine the sensitivity of cells to other apoptotic stimuli [36–39].

Noteworthy, there was marked up-regulation of TP53BP2, an important tumor suppressor gene (TSG) in human cancer, primarily stimulating p53 promotion of apoptosis genes. On the other hand, TP53BP2 is coding ASPP2 protein, which has also been shown to stimulate apoptosis independently of p53 [40–42]. However, Buti et al. recently demonstrated that CagA injected into gastric epithelial cells targeted ASPP2 protein to inhibit p53-mediated apoptosis [12]. The increased TP53BP2 expression seen in our study, might therefore potentiate this effect by increasing the CagA-ASPP2 interaction to cause increased inhibition of p53-mediated apoptosis. In fact, the current study showed that p53 target genes involved in apoptosis [43] such as FAS, DR4, TNFRSF10B (also referred to as DR5/KILLER), DCR1, DCR2, P53AIP1, CASP6, APAF1 and BNIP3L did not show any significant increase, and BNIP3L, CASP6 and APAF1, BID and BAX showed only little increase. p53 target genes regulating non-apoptotic cellular processes including MDM2, GADD45A, CDKN1A (also known as P21 WAF1/CIP1), EGFR, CCND1, CCNG2 and TGFA demonstrated moderate to marked up-regulation. This differential gene expression identified among the p53 target genes in this study, may indicate selective inhibition of p53-mediated apoptosis due to increased CagA-ASPP2 interaction, consistent with Buti’s findings.