Brassinosteroids (BRs) are potent regulators of photosynthesis and crop yield in agricultural crops; however, the mechanism by which BRs increase photosynthesis is not fully understood. Here, we show that foliar application of 24-epibrassinolide (EBR) resulted in increases in CO2 assimilation, hydrogen peroxide (H2O2) accumulation, and leaf area in cucumber. H2O2 treatment induced increases in CO2 assimilation whilst inhibition of the H2O2 accumulation by its generation inhibitor or scavenger completely abolished EBR-induced CO2 assimilation. Increases of light harvesting due to larger leaf areas in EBR- and H2O2-treated plants were accompanied by increases in the photochemical efficiency of photosystem II (ΦPSII) and photochemical quenching coefficient (q P). EBR and H2O2 both activated carboxylation efficiency of ribulose-1,5-bisphosphate oxygenase/carboxylase (Rubisco) from analysis of CO2 response curve and in vitro measurement of Rubisco activities. Moreover, EBR and H2O2 increased contents of total soluble sugar, sucrose, hexose, and starch, followed by enhanced activities of sugar metabolism such as sucrose phosphate synthase, sucrose synthase, and invertase. Interestingly, expression of transcripts of enzymes involved in starch and sugar utilization were inhibited by EBR and H2O2. However, the effects of EBR on carbohydrate metabolisms were reversed by the H2O2 generation inhibitor diphenyleneodonium (DPI) or scavenger dimethylthiourea (DMTU) pretreatment. All of these results indicate that H2O2 functions as a secondary messenger for EBR-induced CO2 assimilation and carbohydrate metabolism in cucumber plants. Our study confirms that H2O2 mediates the regulation of photosynthesis by BRs and suggests that EBR and H2O2 regulate Calvin cycle and sugar metabolism via redox signaling and thus increase the photosynthetic potential and yield of crops.

Although macrophages represent the hallmark of both human and murine atherosclerotic lesions and have been shown to express TGF-ß1 (transforming growth factor β1) and its receptors, it has so far not been experimentally addressed whether the pleiotropic cytokine TGF-ß1 may influence atherogenesis by a macrophage specific mechanism. We developed transgenic mice with macrophage specific TGF-ß1 overexpression, crossed the transgenics to the atherosclerotic ApoE (apolipoprotein E) knock-out strain and quantitatively analyzed both atherosclerotic lesion development and composition of the resulting double mutants. Compared with control ApoE−/− mice, animals with macrophage specific TGF-ß1 overexpression developed significantly less atherosclerosis after 24 weeks on the WTD (Western type diet) as indicated by aortic plaque area en face (p<0.05). Reduced atherosclerotic lesion development was associated with significantly less macrophages (p<0.05 after both 8 and 24 weeks on the WTD), significantly more smooth muscle cells (SMCs; p<0.01 after 24 weeks on the WTD), significantly more collagen (p<0.01 and p<0.05 after 16 and 24 weeks on the WTD, respectively) without significant differences of inner aortic arch intima thickness or the number of total macrophages in the mice pointing to a plaque stabilizing effect of macrophage-specific TGF-ß1 overexpression. Our data shows that macrophage specific TGF-ß1 overexpression reduces and stabilizes atherosclerotic plaques in ApoE-deficient mice.

To investigate the prevalence of Enterococcus faecalis in saliva and filled root canals of patients requiring endodontic retreatment for apical periodontitis. Patients with apical periodontitis who were referred for endodontic retreatment were examined. The type and quality of the restoration, symptoms, quality of obturation were recorded. During retreatment, an oral rinse sample and root canal sample were cultured using brain-heart infusion agar and bile esculinazide agar to select for E. faecalis. The 16S rRNA technique was used to identify E. faecalis. A total of 32 women and 22 men (mean age: 38 years; s.d.: 11 years) and 58 teeth were studied. The prevalence of E. faecalis was 19% in the saliva and 38% in the root canals. The odds that root canals harbored E. faecalis were increased if the saliva habored this bacterium (odds ratio=9.7; 95% confidence interval=1.8–51.6; P<0.05). Teeth with unsatisfactory root obturation had more cultivable bacterial species in root canals than teeth with satisfactory root obturation (P<0.05). E. faecalis is more common in root canals of teeth with apical periodontitis than in saliva. The prevalence of E. faecalis in root canals is associated with the presence of E. faecalis in saliva.

N-ethyl-N-nitrosourea (ENU) mutagenesis is a useful approach for genetic improvement of plants, as well as for inducing functional mutants in animal models including mice and zebrafish. In the present study, mature sperm of grass carp (Ctenopharyngodon idellus) were treated with a range of ENU concentrations for 45 min, and then wild-type eggs were fertilized. The results indicated that the proportion of embryos with morphological abnormalities at segmentation stage or dead fry at hatching stage increased with increasing ENU dose up to 10 mM. Choosing a dose that was mutagenic, but provided adequate numbers of viable fry, an F1 population was generated from 1 mM ENU-treated sperm for screening purposes. The ENU-treated F1 population showed large variations in growth during the first year. A few bigger mutants with morphologically normal were generated, as compared to the controls. Analysis of DNA from 15 F1 ENU-treated individuals for mutations in partial coding regions of igf-2a, igf-2b, mstn-1, mstn-2, fst-1and fst-2 loci revealed that most ENU-treated point mutations were GC to AT or AT to GC substitution, which led to nonsense, nonsynonymous and synonymous mutations. The average mutation rate at the examined loci was 0.41%. These results indicate that ENU treatment of mature sperm can efficiently induce point mutations in grass carp, which is a potentially useful approach for genetic improvement of these fish.

Primary culture of smooth muscle cells has been widely used as a valuable tool to study the molecular mechanisms underlying atherosclerosis and restenosis. Currently, tissue explants and enzymatic digestion methods are frequently applied to produce smooth muscle cells. Explants method is time consuming, usually taking several weeks. The enzymatic digestion method requires large amounts of proteolytic enzymes to generate enough cells for cardiovascular research. The present study reports an optimized method by combining both techniques to obtain high purity smooth muscle cells. The cultured cells exhibited the characteristic “hills and valleys” growth pattern as observed by phase contrast microscopy and showed α-SM-actin positive staining by indirect immunocytochemistry and immunofluorescence. Purity of the cells is guaranteed by the lack of von Willebrand Factor immunoreactivity. Finally, the cultured cells well proliferate on oxidized-LDL stimulation, suggesting the practical utility of this new method.