Methylated polyphenols are poor "chemical" antioxidants but can still effectively protect cells from hydrogen peroxide-induced cytotoxicity

Several polyphenolic compounds, including flavonoids and phenolic acids, were compared with their per-methylated forms in both chemical and cell-based assays for antioxidant capacity. Methylation largely eliminated "chemical" antioxidant capacity, according to ferric reducing antioxidant power and oxygen radical absorbance capacity assays. Methylation, however, only moderately reduced protection of human Jurkat cells in culture, from hydrogen peroxide-mediated cytotoxicity, at physiologically relevant concentrations. Neither methylated nor un-methylated compounds were detectably metabolized by the cells. It appears that the protective mechanism of polyphenolic antioxidants against high concentrations of hydrogen peroxide in human cells may be largely unrelated to chemical antioxidant capacity.     

Random regression analysis for body weights and main morphological traits in genetically improved farmed tilapia (<Emphasis Type=Italic>Oreochromis niloticus</Emphasis>)

To genetically analyse growth traits in genetically improved farmed tilapia (GIFT), the body weight (BWE) and main morphological traits, including body length (BL), body depth (BD), body width (BWI), head length (HL) and length of the caudal peduncle (CPL), were measured six times in growth duration on 1451 fish from 45 mixed families of full and half sibs. A random regression model (RRM) was used to model genetic changes of the growth traits with days of age and estimate the heritability for any growth point and genetic correlations between pairwise growth points. Using the covariance function based on optimal RRMs, the heritabilities were estimated to be from 0.102 to 0.662 for BWE, 0.157 to 0.591 for BL, 0.047 to 0.621 for BD, 0.018 to 0.577 for BWI, 0.075 to 0.597 for HL and 0.032 to 0.610 for CPL between 60 and 140 days of age. All genetic correlations exceeded 0.5 between pairwise growth points. Moreover, the traits at initial days of age showed less correlation with those at later days of age. With phenotypes observed repeatedly, the model choice showed that the optimal RRMs could more precisely predict breeding values at a specific growth time than repeatability models or multiple trait animal models, which enhanced the efficiency of selection for the BWE and main morphological traits.     

Influence of epistatic segregation distortion loci on genetic marker linkages in Japanese flounder

For genetic linkage analysis of Japanese flounder, 160 doubled haploids (DH) were artificially produced using mitotic gynogenesis and were genotyped for 458 simple sequence repeat (SSR) markers, 101 of which show distortional segregation. The genetic linkage map was constructed by modifying recombination fractions between the distorted markers. Between the corrected and uncorrected genetic maps, there were considerable differences in genetic distance, but not in relative locations among markers. Using a liability model, a segregation distortion locus (SDL), with an additive genetic effect of 1.772, was mapped between markers BDHYP387 and Poli56TUF of chromosome 24 in the corrected genetic map. Additionally, six pairs of epistatic SDLs were identified on chromosomes 1, 5, 8, 9, 23, and 24. Changes in genetic distances between markers did not occur on chromosome regions with main effect SDLs. However, most chromosome regions where genetic distances changed covered the detected epistatic SDLs. This study concluded that epistatic SDLs decrease linkages between markers and lengthen genetic distances in Japanese flounder. This finding has been partially validated in other DH populations derived from three female Japanese flounders.     

FSH mediates estradiol synthesis in hypoxic granulosa cells by activating glycolytic metabolism through the HIF-1α–AMPK–GLUT1 signaling pathway

Owing to the avascular environment within ovarian follicles, granulosa cells (GCs) are believed to live in a hypoxic niche. Follicle-stimulating hormone (FSH)-mediated steroidogenesis is crucial for normal growth and maturation of ovarian follicles, but it remains unclear how FSH stimulates estradiol (E2) synthesis under hypoxic conditions. Here, we aimed to explore whether FSH affects the ATP production required for estrogen synthesis from the perspective of glucose metabolism. It was observed that the levels of both E2 and HIF-1α were markedly increased in a dose-dependent manner in mouse ovarian GCs after the injection of FSH in vivo, indicating that hypoxia/HIF-1α may be relevant to FSH-induced E2 synthesis. By treating hypoxic GCs with FSH in vitro, we further revealed that the activation of the AMP-activated protein kinase (AMPK)–GLUT1 pathway, which in turn stimulates ATP generation, may be essential for FSH-mediated E2 production during hypoxia. In contrast, inhibition of AMPK or GLUT1 with siRNAs/antagonist both repressed glycolysis, ATP production, and E2 synthesis despite FSH treatment. Moreover, blocking HIF-1α activity using siRNAs/PX-478 suppressed AMPK activation, GLUT1 expression, and E2 levels in FSH-treated GCs. Finally, the in vitro findings were verified in vivo, which showed markedly increased AMPK activity, GLUT1 expression, glycolytic flux, ATP levels, and E2 concentrations in ovarian GCs following FSH injection. Taken together, these findings uncovered a novel mechanism for FSH-regulating E2 synthesis in hypoxic GCs by activating glycolytic metabolism through the HIF-1α–AMPK–GLUT1 pathway.     

Synthesis and biological evaluation of novel F-18 labeled pyrazolo[1,5-a]pyrimidine derivatives: potential PET imaging agents for tumor detection

Two novel pyrazolo[1,5-a]pyrimidine derivatives, 7-(2-[¹⁸F]fluoroethylamino)-5-methylpyrazolo[1,5-a]pyrimidine-3-carbonitrile ([¹⁸F]FEMPPC, [¹⁸F]1) and N-(2-(3-cyano-5-methylpyrazolo[1,5-a]pyrimidin-7-ylamino)ethyl)-2-[¹⁸F]fluoro-4-nitrobenzamide ([¹⁸F]FCMPPN, [¹⁸F]2), have been designed and successively labeled with ¹⁸F by the nucleophilic substitution employing tosylate and nitryl as leaving groups, respectively. The radiochemical synthesis of both compounds was completed within 60 min with final high-performance liquid chromatography purification included. The corresponding radiochemical yields (without decay correction) were approximately 35% and 30%, respectively. Meanwhile, we compared the uptake characteristics of [¹⁸F]1 and [¹⁸F]2 with those of [¹⁸F]FDG and L-[¹⁸F]FET in S180 tumor cells. Furthermore, the tumor uptake of [¹⁸F]1 and [¹⁸F]2 was assessed in mice bearing S180 tumor and compared with [¹⁸F]FDG and L-[¹⁸F]FET in the same animal model. In vitro cell uptake studies showed [¹⁸F]1 had higher uptake than [¹⁸F]FDG, [¹⁸F]2 and L-[¹⁸F]FET over the 2 h period. In ex vivo biodistribution showed tumor/brain uptake ratios of [¹⁸F]2 were 12.35, 10.44, 8.69 and 5.13 at 15 min, 30 min, 60 min and 120 min post-injection, much higher than those of L-[¹⁸F]FET (2.43, 2.54, 2.93 and 2.95) and [¹⁸F]FDG (0.59, 0.61, 1.02 and 1.33) at the same time point. What’s more, the uptake of [¹⁸F]1 in tumor was 1.88, 4.37, 5.51, 2.95 and 2.88 at 5 min, 15 min, 30 min, 60 min and 120 min post-injection, respectively. There was a remarkable increasing trend before 30 min. The same trend was present for L-[¹⁸F]FET before 30 min and [¹⁸F]FDG before 60 min. Additionally, the tumor/brain uptake ratios of [¹⁸F]1 were superior to those of [¹⁸F]FDG at all the selected time points, the tumor/muscle and tumor/blood uptake ratios of [¹⁸F]1 at 30 min were higher than those of L-[¹⁸F]FET at the same time point. MicroPET image of [¹⁸F]1 administered into S180 tumor-bearing mouse acquired at 30 min post-injection illustrated that the uptake in S180 tumor was obvious. These results suggest that compound [¹⁸F]1 could be a new probe for PET tumor imaging.     

The purification and characterization of a novel alkali-stable pectate lyase produced by <Emphasis Type="Italic">Bacillus subtilis</Emphasis> PB1

Pectinase is an important kind of enzyme with many industrial applications, among which pectinases produced by bacteria were scarce compared with fungal sources. In this study, a novel bacterium which produced extracellular pectinase was firstly isolated from flue-cured tobacco leaves and identified as Bacillus subtilis PB1 according to its 16S rRNA gene. The pectinolytic enzyme was purified by ammonium sulfate precipitation, ion-exchange and gel filtration chromatography, after which molecular weight was determined as 43.1?±?0.5 kDa by SDS–PAGE. Peptide mass fingerprinting of the pectinase by MALDI-TOF MS showed that the purified enzyme shared homology with pectate lyase and was designated as BsPel-PB1. The optimal temperature for BsPel-PB1 was 50 °C. The optimal pH was pH 9.5 for BsPel-PB1 while it had a broad pH stability from 5 to 11. The values of K _m and V _max were 0.312 mg/mL and 1248 U/mL, respectively. Accordingly, the BsPel-PB1 was a novel alkaline pectate lyase which could find potential application as a commercial candidate in the pectinolytic related industries.     

Synthesis and evaluation of novel F-18 labeled fluoroarylvaline derivatives: Potential PET imaging agents for tumor detection

Two F-18 labeled fluoroarylvaline derivatives, methyl 2-(2-[¹⁸F]fluoro-4-nitrobenzamido)-3-methylbutanoate ([¹⁸F]1, [¹⁸F]MFNBMB) and its corresponding acid 2-(2-[¹⁸F]fluoro-4-nitrobenzamido)-3-methylbutanoic acid ([¹⁸F]2, [¹⁸F]FNBMBA), have been designed and synthesized, respectively, by our team. Meanwhile, we research on their biodistributions in mice model bearing S 180 tumor. Furthermore, we also carried out the biological evaluations of 2-[¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) and O-2-[¹⁸F]fluoroethyl-l-tyrosine (l-[¹⁸F]FET) in the same model for comparison with our targeting molecules [¹⁸F]1 and [¹⁸F]2. Excitingly, the tumor/blood (T/Bl) and tumor/brain (T/Br) ratios were 2.91, 7.06 at 30 min, 3.44, 5.61 at 60 min post injection for [¹⁸F]1, 2.32, 13.30 for [¹⁸F]2 at 30 min post injection, which were obviously superior to [¹⁸F]FDG and l-[¹⁸F]FET in the same model and demonstrated that [¹⁸F]1 and [¹⁸F]2, especially [¹⁸F]2, were potential PET imaging agents for tumor detection.     

Cellular and clinicopathological features of the IL-33/ST2 axis in human esophageal squamous cell carcinomas

Background

Emerging evidence has suggested that interleukin (IL)-33 and its primary functional receptor ST2 are involved in the pathogenesis of tumorigenesis.

Methods

Using immunohistochemistry (IHC) and double immunofluorescence staining, we characterized the cellular and clinicopathological features of the IL-33/ST2 axis in different compartments in human esophageal squamous cell carcinoma (ESCC) surgical specimens.

Results

IHC data revealed an increased expression of IL-33-immunoreactivity (IR) and ST2-IR located in both ESCC cells and tumor stromal cells; which were associated with advanced clinicopathological features such as TNM stages and node involvement. However, the Kaplan–Meier analysis showed that densities of neither IL-33 positive nor ST2 positive cells in both the ESCC mass and stroma were associated with the overall survival rate in patients with ESCC. Double immunofluorescence staining for cellular feature analysis demonstrated that these IL-33 positive and ST2 positive cells in ESCCs were with a high proliferation rate, and IL-33-IR was frequently co-expressed with ST2-IR in both ESCC and stromal cells.

Conclusion

Significant altered cellular features of the IL-33/ST2 axis in ESCCs were associated with advanced clinicopathological variables. The data suggest that the IL-33/ST2 axis might be involved in the progression of human ESCCs.

     

A New Exponential Ratio-Type Estimator with Linear Combination of Two Auxiliary Variables

In sample surveys, it is usual to make use of auxiliary information to increase the precision of estimators. We propose a new exponential ratio-type estimator of a finite population mean using linear combination of two auxiliary variables and obtain mean square error (MSE) equation for proposed estimator. We find theoretical conditions that make proposed estimator more efficient than traditional multivariate ratio estimator using information of two auxiliary variables, the estimator of Bahl and Tuteja and the estimator proposed by Abu-Dayeh et al. In addition, we support these theoretical results with the aid of two numerical examples.