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Background Cold-inducible RNA-binding protein is a novel damage-associated molecular pattern that causes inflammation. C23, a short peptide derived from cold-inducible RNA-binding protein, has been found to have efficacy in blocking cold-inducible RNA-binding protein's activity. We hypothesized that C23 reduces inflammation and tissue injury induced by intestinal ischemia-reperfusion. Methods Male C57BL/6 mice were subjected to 60 minutes of intestinal ischemia by clamping the superior mesenteric artery. Immediately after reperfusion, either normal saline (vehicle) or C23 peptide (8 mg/kg body weight) was injected intraperitoneally. Four hours after reperfusion, blood, intestinal, and lung tissues were collected for analysis of inflammatory and tissue injury parameters. Results Cold-inducible RNA-binding protein levels in the intestinal tissues were significantly increased following intestinal ischemia-reperfusion. Histologic examination of the intestine revealed a significant reduction in injury score in the C23 group by 48% as compared with the vehicles after intestinal ischemia-reperfusion. The serum levels of lactate dehydrogenase and aspartate aminotransferase were increased in animals that underwent vehicle-treated intestinal ischemia-reperfusion, whereas C23-treated animals exhibited significant reductions by 48% and 53%, respectively. The serum and intestinal tissue levels of tumor necrosis factor α were elevated in vehicle-treated intestinal ischemia-reperfusion mice but decreased by 72% and 69%, respectively, in C23-treated mice. Interleukin-6 mRNA levels in the lungs were reduced by 86% in the C23-treated group in comparison to the vehicle-treated group after intestinal ischemia-reperfusion. Expression of macrophage inflammatory protein 2 and level of myeloperoxidase activity in the lungs were dramatically increased after intestinal ischemia-reperfusion and significantly reduced by 91% and 25%, respectively, in the C23-treated group. Conclusion C23 has potential to be developed into a possible therapy for reperfusion injury after mesenteric ischemia and reperfusion. [ABSTRACT FROM AUTHOR]

The utilization of computer modeling, site-directed mutagenesis, inhibition kinetic analysis and reaction metabolite analysis allows us to better understand the structure–function relationship between aromatase and its inhibitors. Our results have helped in determining how steroidal and nonsteriodal aromatase inhibitors bind to the active site of the enzyme. This information has also aided in the understanding of the reaction mechanism of aromatase. Furthermore, our structure–function studies of aromatase have generated important information for predicting how environmental chemicals interact with the enzyme. During the last 2 years, a new aromatase computer model based on the X-ray structure of rabbit cytochrome P450 2C5 has been generated and used to evaluate the results obtained from new aromatase mutants produced in this laboratory. In addition, we have succeeded in the expression and purification of functionally active aromatase using an Escherichia coli expression method. The catalytic properties of this recombinant aromatase are similar to those properties exhibited by the human placental aromatase preparation and the mammalian cell-expressed enzyme. The E. coli expressed aromatase will be very useful for further structure–function studies of aromatase. Our laboratory has also evaluated the growth-inhibiting activity of aromatase inhibitors in estrogen receptor-positive breast cancer using three-dimensional cell cultures of aromatase-over expressing MCF-7 and T-47D cell lines (i.e. MCF-7aro and T-47Daro). Our results demonstrate that these three-dimensional cultures are valuable approaches to assess the growth-inhibiting activity of aromatase inhibitors. Finally, we have identified several phytochemicals to be potent inhibitors of aromatase. To demonstrate the impact of the phytochemicals on estrogen formation in vivo, we showed that the intake of anti-aromatase chemicals from red wine was capable of suppressing MCF-7aro-mediated tumor formation in nude mice and aromatase-induced hyperplasia in a transgenic mouse model in which aromatase is over-expressed in the mammary tissue. [Copyright &y& Elsevier]

Aromatase converts androgen to estrogen, a hormone that plays an important role in the development of breast cancer. Aromatase inhibitors have been shown to be a useful endocrine regimen for estrogen-dependent breast cancer. Structure–function studies of aromatase can generate critical structural information for designing highly potent and specific inhibitors. However, aromatase structure–function studies have been hampered by a lack of purified protein. In this report, we describe the construction and expression of a recombinant derivative of human aromatase in Escherichia coli using the pET vector system, and the purification of the enzyme by means of nickel-agarose affinity chromatography. We examined the expression of the full-length, Del-38, C-6xHis-tagged Del-38, and NC-6xHis-tagged Del-38 forms of aromatase. The recombinant aromatase without the first 38 amino acids from the amino-terminus (i.e. Del-38) was found to have a higher activity than the full-length enzyme. Moreover, the addition of two separate hexameric histidine tags at both the amino and the carboxyl-termini (i.e. NC-6xHis-tagged Del-38) increased the binding affinity of the recombinant enzyme to the nickel-agarose. The expressed aromatase (i.e. NC-6xHis-tagged Del-38 aromatase) was eluted from the nickel-agarose with 80 mM EDTA. The total aromatase activity of the 80 mM EDTA-eluted fractions was significantly higher than the detergent-solubilized protein extract, indicating a renaturation process during the nickel-agarose affinity chromatography. Purified aromatase exhibited a single band when analyzed by SDS–PAGE, and activity up to 5.8 nmol/mg/min was obtained using the tritiated water release assay. The Km value for androstenedione was determined to be 62±24 nM by enzyme kinetic analysis. The recombinant aromatase preparation was also characterized by reduced CO-difference spectral analysis, reaction product extraction assay, and inhibition studies using two aromatase inhibitors (letrozole and anastrozole). The results indicate that the recombinant aromatase from E. coli has catalytic properties identical to those of the enzyme expressed in human tissue and will be very useful for further structure–function studies of aromatase. [Copyright &y& Elsevier]

In analyzing the effect of alkali metal and alkaline earth metal oxide on the properties of tellurite glass, a series of tellurite glass samples doped with alkali metals and alkaline earth metals were prepared based on the TeO 2 -WO 3 -GdF 3 glass system by melt quenching method. Through tests and comprehensive analysis, the results show that after the F− ions successfully enter the glass network, the substitution of TeO 2 by alkali and alkaline earth metals could reduce the molar volume, which means the glass becomes more compacted. The influence on the glass network is mainly shown in [TeO 3 ] and [TeO 4 ] units. Alkali metals and alkaline earth metals could increase the asymmetry of the TWG: Eu3+ glass network, shorten the critical distance, and increase luminescence intensity by 8.6 times and improve color purity to 94%. In addition, alkali metals could prolong the fluorescence lifetime, while alkaline earth metals could shorten it. Te4+ [ABSTRACT FROM AUTHOR]

In the TeO 2 -WO 3 -GdF 3 glass system, 42 different proportions of glass have been prepared, showing the ideal forming area. The influence of proportions on the density was measured and several devitrified samples were analyzed by XRD. Discussed the internal structure changes and the variation of component concentration by Raman and Fourier transform infrared spectra. The properties and structural features of glasses were analyzed in terms of molar volume. TeO 2 and WO 3 act as glasses former while GdF 3 act as a modifier which forms mixed linkages Te–O–W, Te–F–W, etc. UV–Vis spectra were recorded to determine optical absorption/transmission and energy gap values. These results suggest that the TeO 2 -WO 3 -GdF 3 glass system could be potentially used as photonic devices and basic materials. [ABSTRACT FROM AUTHOR]