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Biocompatible materials and biocarriers have attracted great attention in biological wastewater treatment owing to their excellent performance in improving pollutant removal. Graphene-based material, a biocarrier candidate, with excellent adsorbability and conductivity was increasingly applied in anaerobic digestion due to its exceptional potential in the adsorption and electron transfer process. Nevertheless, the green approach for the formation of bio-graphene complexes and their mechanism in dye removal is limited. The aim of this study is to investigate and assess the performance of biological graphene hydrogel (BGH) formed by Shewanella putrefaciens CN32 on the removal of methyl orange (MO) and methylene blue (MB). The results showed that the formation of BGH is determined by the physicochemical characteristics of graphene oxide, including sheet size, oxidation degree, and interlayer distance. BGHs significantly increased the removal efficiency of dyes in comparison to non-graphene samples, with a 24-h removal rate of MO and MB reaching 92.9% and 91%, respectively. The synergetic mechanism of BGH on the enhanced removal rate of organic dye can be ascribed to GO's ability in accelerating extracellular electron transfer and stimulating biodegradation pathways relating to c -type cytochromes, including MtrA and MtrC. These findings provided an understanding of the relationship between graphene-based nanomaterials and Shewanella , which facilitated their future application in environmental biotechnology. [Display omitted] • The reduction of GO by S. putrefaciens CN32 prompt BGH generation. • Sheet area and degree of defects of GO determine the BGH formation. • Bacteria-immobilized rGO hydrogel displayed a synergistic effect in bioremediation. • BGH increased dye removal efficiency by accelerating extracellular electron transfer. [ABSTRACT FROM AUTHOR]

A new series of ligustrazine-cinnamon acid derivatives had been designed and synthesized as potential neuro-protective agents. Among the derivatives, 3a exhibited the promising neuroprotective activity (EC 50  = 3.68 μM). Moreover, with the deep research of the drug pathway, it (the further mechanism researches) suggested compound 3a could inhibit the apoptosis of injured PC12 cells via blocking the mitochondria apoptosis pathway including up-regulation the ratio of Bcl-2/Bax, down-regulation the expression of cytochrome- c (Cyt- c ) and inhibition of the activity of caspase-9 and -3. In addition, the structure-activity relationships (SARs) of novel compounds were also discussed. [ABSTRACT FROM AUTHOR]

Abstract: Published data on the association between CYP1A1 gene polymorphism and ovarian cancer risk are conflicting and heterogeneous. To derive a more precise estimation of the relationship, a meta-analysis was performed. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were performed for heterozygous, homozygous, dominant model, recessive model and allele, respectively. A total of 15 case–control studies were identified, among which, 13 studies (1815 cases and 3501 controls) were eligible for CYP1A1 Ile462Val and nine studies (2495 cases and 3553 controls) were eligible for CYP1A1 Msp1. Overall, Ile462Val was significantly associated with ovarian cancer, with homozygous carriers (Val/Val vs. Ile/Ile: OR=2.64; 95% CI: 1.63–4.28) and recessive model (Val/Val vs. Ile/Ile and Ile/Val: OR=2.30; 95% CI: 1.45–3.65) being risk factors for ovarian cancer development. In the subgroup analysis by ethnicity, significantly increased risks were found for Caucasians (homozygous carriers: OR=4.91; 95% CI: 2.07–11.66; recessive model: OR=3.26; 95% CI: 1.41–7.50) and Asians (homozygous carriers: OR=3.06; 95% CI: 1.48–6.33; recessive model: OR=2.75; 95% CI: 1.40–5.41; Val allele: OR=1.67; 95% CI: 1.19–2.35). However, no significant associations were found between Msp1 and ovarian cancer in the overall analyses or the subgroup analyses by ethnicity. This meta-analysis denotes the importance for in-depth research regarding of gene–gene, gene–environment interactions, race-specific and histological subtypes specific to obtain a more conclusive response about the function of CYP1A1 in ovarian cancer. [Copyright &y& Elsevier]

Abstract: We have previously demonstrated that over-expression of spike protein (S) of severe acute respiratory syndrome coronavirus (SARS-CoV) or its C-terminal subunit (S2) is sufficient to induce apoptosis in vitro. To further investigate the possible roles of S2 in SARS-CoV-induced apoptosis and pathogenesis of SARS, we characterized the host expression profiles induced upon S2 over-expression in Vero E6 cells by oligonucleotide microarray analysis. Possible activation of mitochondrial apoptotic pathway in S2 expressing cells was suggested, as evidenced by the up-regulation of cytochrome c and down-regulation of the Bcl-2 family anti-apoptotic members. Inhibition of Bcl-2-related anti-apoptotic pathway was further supported by the diminution of S2-induced apoptosis in Vero E6 cells over-expressing Bcl-xL. In addition, modulation of CCN E2 and CDKN 1A implied the possible control of cell cycle arrest at G1/S phase. This study is expected to extend our understanding on the pathogenesis of SARS at a molecular level. [Copyright &y& Elsevier]

Abstract: The interaction of metalloproteins with oxides has implications not only for bioanalytical systems and biosensors but also in the areas of biomimetic photovoltaic devices, bioremediation, and bacterial metal reduction. Here, we investigate mitochondrial ferricytochrome c (Cyt c) co-sorption with 0.01 and 0.1 M phosphate on hematite (α-Fe2O3) surfaces as a function of pH (2–11). Although Cyt c sorption to hematite in the presence of phosphate is consistent with electrostatic attraction, other forces act upon Cyt c as well. The occurrence of multilayer adsorption, and our AFM observations, suggest that Cyt c aggregates as the pH approaches the Cyt c isoelectric point. In solution, methionine coordination of heme Fe occurs only between pH 3 and 7, but in the presence of phosphate this coordination is retained up to pH 10. Electrochemical evidence for the presence of native Cyt c occurs down to pH 3 and up to pH 10 in the absence of phosphate, and this range is extended to pH 2 and 11 in the presence of phosphate. Cyt c that initially adsorbs to a hematite surface may undergo conformation change and coat the surface with unfolded protein such that subsequently adsorbing protein is more likely to retain the native conformational state. AFM provides evidence for rapid sorption kinetics for Cyt c co-sorbed with 0.01 or 0.1 M phosphate. Cyt c co-sorbed with 0.01 M phosphate appears to unfold on the surface of hematite while Cyt c co-sorbed with 0.1 M phosphate possibly retains native conformation due to aggregation. [Copyright &y& Elsevier]

Abstract: We examined whether a −34T → C polymorphism of the gene for cytochrome P450, family 17, subfamily A, polypeptide 1 (CYP17A1), a −493G → T polymorphism of the microsomal triglyceride transfer protein gene (MTP), and a CGG repeat polymorphism of the very low density lipoprotein receptor gene (VLDLR) were associated with bone mineral density (BMD) in community-dwelling Japanese women and men. The −34T → C polymorphism of CYP17A1 was associated with BMD in postmenopausal women, with the CC genotype being related to increased BMD. The −493G → T polymorphism of MTP was associated with BMD in premenopausal women, with the TT genotype being related to increased BMD. The CGG repeat polymorphism of VLDLR was associated with BMD in men, with two (CGG) n ≥ 8 alleles being related to increased BMD. These results suggest that CYP17A1 and MTP are susceptibility loci for increased BMD in postmenopausal and premenopausal Japanese women, respectively, and that VLDLR constitutes such a locus in Japanese men. [Copyright &y& Elsevier]

Abstract: In several cell types, poliovirus activates the apoptotic program, implementation of which is suppressed by viral antiapoptotic functions. In such cells, productive infection leads to a necrotic cytopathic effect (CPE), while abortive reproduction, associated with inadequate viral antiapoptotic functions, results in apoptosis. Here, we describe two other types of cell response to poliovirus infection. Murine L20B cells expressing human poliovirus receptor responded to the infection by both CPE and apoptosis concurrently. Interruption of productive infection decreased rather than increased the proportion of apoptotic cells. Productive infection was accompanied by the early efflux of cytochrome c from the mitochondria in a proportion of cells and by activation of DEVD-specific caspases. Inactivation of caspase-9 resulted in a marked, but incomplete, prevention of the apoptotic response of these cells to viral infection. Thus, the poliovirus-triggered apoptotic program in L20B cells was not completely suppressed by the viral antiapoptotic functions. In contrast, human rhabdomyosarcoma RD cells did not develop appreciable apoptosis during productive or abortive infection, exhibiting inefficient efflux of cytochrome c from mitochondria and no marked activation of DEVD-specific caspases. The cells were also refractory to several nonviral apoptosis inducers. Nevertheless, typical caspase-dependent signs of apoptosis in a proportion of RD cells were observed after cessation of viral reproduction. Such “late” apoptosis was also observed in productively infected HeLa cells. In addition, a tiny proportion of all studied cells were TUNEL positive even in the presence of a caspase inhibitor. Degradation of DNA in such cells appeared to be a postmortem phenomenon. Biological relevance of variable host responses to viral infection is discussed. [Copyright &y& Elsevier]

Cytochrome b5/cytochrome b5 reductase (cb5/cb5r) is a cytosolic fusion protein between the hemoprotein cytochrome b5 and the flavoprotein cytochrome b5 reductase. We describe the identification and characterization of a novel splice variant of cb5/cb5r in the mouse and rat and show that expression of the variant is conserved in both species but is not expressed in human tissue. Characterization of the exon structure of cb5/cb5r indicated that the variant was due to the deletion of the whole of exon 12, thus the variant was named cb5/cb5rΔ12. Exon 12 codes for the flavin-adenine dinucleotide binding domain of cb5/cb5r. Expression analysis revealed the transcript of cb5/cb5rΔ12 in mouse and rat testis, brain, and skeletal muscle and also in the male germ line. We postulate that cb5/cb5rΔ12 may function in a dominant negative fashion, limiting the amount of damage caused by the production of reactive oxygen species by cb5/cb5r. [Copyright &y& Elsevier]

Urinary 1-hydroxypyrene (1-OHP) has been used as a biomarker for environmental polyaromatic hydrocarbon (PAH) exposure. However, it is known that there is an interindividual variability in metabolism of pyrene to 1-OHP depending on the activities of the metabolizing enzymes, especially cytochrome P450s (CYPs). In this study, we investigated the 1-hydroxylation of pyrene by 10 forms of cDNA-expressed human P450s in order to identify the principal isoforms of P450s that are involved in the major metabolic pathway of pyrene. The pyrene 1-hydroxylation activity was found to be the highest in CYP1A1 at both 0.5 and 50 μM of pyrene, followed by CYP1B1 and 1A2, whereas other enzymes, including CYP2A6, 2C8, 2C9*1, 2C19, 2D6, 2E1, 3A4, and control microsomes, showed very low or undetectable rates of 1-hydroxylation. In conclusion, CYP1A1, 1B1, and 1A2 are major metabolizing enzymes in 1-hydroxylation of pyrene in vitro. This suggests that the individual difference of these enzymes must be included in epidemiological studies to evaluate PAH exposure using urinary 1-OHP. [Copyright &y& Elsevier]

Cytochromes P4501B1 (CYP1B1) and P4501A1 (CYP1A1) are involved in the metabolic activation of many polycyclic aromatic hydrocarbons (PAH). To investigate the variability of these enzymes in humans a long-term study of the constitutive mRNA expression in peripheral blood mononuclear cells (PBMC) was initiated. Blood samples were collected from 16 volunteers of both sexes every second month during a 20-month period in 1999 and 2000. mRNA expression was quantified using a competitive reverse transcription-PCR method. The monocyte content in PBMC was determined using a fluorescence-activated cell sorter. To study the effect of genotype, polymorphisms in CYP1B1, CYP1A1, and glutathione transferase M1 (GSTM1) were determined by PCR-based methods. Information about environmental PAH exposure and solar radiation was obtained through questionnaires and solar radiation records. Since the levels of CYP1A1 mRNA were found to be extremely low (at or below the detection level), only CYP1B1 mRNA levels were quantified. The maximum range of CYP1B1 mRNA expression across different blood collection time points and subjects was 30-fold (1670–49,900 CYP1B1 mRNA molecules/106 β-actin mRNA molecules). The individual average levels of expression ranged from 8520 to 12,700 CYP1B1 mRNA molecules/106 β-actin mRNA molecules (a 2.3-fold variation), with an average level of 12,700 CYP1B1 mRNA molecules/106 β-actin mRNA molecules. A pronounced variation in CYP1B1 expression between the different time points of blood collection was observed. The intraindividual variation of CYP1B1 expression during the 20-month study period was from 3- to 21-fold (average 9-fold) and the average interindividual fold variation, at one time point, was 8 (range 3–16). An association between solar radiation records and CYP1B1 mRNA expression was suggested. This correlation was significant for the year 2000 (rs=0.30, P=0.012). No or weak effects of age, gender, monocyte content in total PBMC, recent PAH exposure, or genetic polymorphisms in CYP1B1, CYP1A1, or GSTM1 were observed. [Copyright &y& Elsevier]

Biologically synthesized palladium nanoparticles (bio-Pd) have attracted considerable interest as promising green catalysts for environmental remediation. However, the mechanisms by which microorganisms produce bio-Pd remain unclear. In the present study, we investigated the roles of Shewanella oneidensis MR-1 and its NADH dehydrogenases and hydrogenases (HydA and HyaB) in bio-Pd production using formate as the electron donor. The roles of NADH dehydrogenases and hydrogenases were studied by inhibiting NADH dehydrogenases and using hydrogenase mutants (Δ hydA , Δ hyaB , and Δ hydA Δ hyaB), respectively. The results showed ~97% reduction of palladium by S. oneidensis MR-1 after 24 h using 250 μM palladium and 500 μM formate. Electron microscopy images showed the presence of bio-Pd on both the outer and cytoplasmic membranes of S. oneidensis MR-1. However, the inhibition of NADH dehydrogenases in S. oneidensis MR-1 resulted in only ~61% reduction of palladium after 24 h, and bio-Pd were not found on the outer membrane. The mutants lacking one or two hydrogenases removed 91–96% of palladium ions after 24 h and showed more cytoplasmic bio-Pd but less periplasmic bio-Pd. To the best of our knowledge, this is the first study to demonstrate the role of NADH dehydrogenases of S. oneidensis MR-1 in the formation of bio-Pd on the outer membrane. It also demonstrates that the hydrogenases (especially HyaB) of S. oneidensis MR-1 contribute to the formation of bio-Pd in the periplasmic space. This study provides mechanistic insights into the production of biogenic metal nanoparticles towards their possible use in industrial and environmental applications. • S. oneidensis MR-1 deposited bio-Pd on both the outer and cytoplasmic membranes. • The inhibition of NADH dehydrogenases in S. oneidensis MR-1 significantly slowed down the Pd(II) reduction. • The NADH dehydrogenases in S. oneidensis MR-1 participated in the formation of bio-Pd on the outer membrane. • The hydrogenase mutants of S. oneidensis MR-1 produced less periplasmic bio-Pd and more cytoplasmic bio-Pd. • The hydrogenases in S. oneidensis MR-1 promoted the formation of bio-Pd in the periplasmic space. [ABSTRACT FROM AUTHOR]