The inhibitory effect of a polysaccharide from Codonopsis pilosula on tumor growth and metastasis in vitro

In this study, we prepared an acidic polysaccharide (CPPA) from the roots of Codonopsis pilosula. The effects of CPPA on tumor cell growth, invasion, and migration were examined in vitro. The CPPA not only induced a potent inhibitory effect on the invasion and migration potential of human epithelial ovarian cancer HO-8910 cells in vitro, evaluated by wound healing, transwell and cell adhesion assays, but also had an efficient anti-proliferation effect on tumor cells. Moreover, the CD44 expression on the HO-8910 cells was also attenuated by CPPA treatment. Therefore, our results indicate that CPPA may be a potential candidate compound for the prevention of tumor metastasis, presumably by inhibiting invasion, migration and adhesion of tumor cells, as well as the CD44 expression on the tumor cells.     

Synergistic interactions between Glomus mosseae and Bradyrhizobium japonicum in enhancing proton release from nodules and hyphae

Soybean (Glycine max L. Merr.) seedlings were inoculated with Glomus mosseae (GM) and Bradyrhizobium japonicum (BJ) together or separately to study the effect of interactions on net H⁺ effluxes of nodules or extraradical hyphae by in vivo vibrating electrode techniques. GM promoted three-fold the H⁺ effluxes of nodules on mycorrhizal lateral roots and BJ increased eight-fold the net H⁺ effluxes of hyphae developing in the vicinity of nodules on lateral roots. Increments in plant P content were positively and linearly correlated with the net H⁺ efflux of nodules and hyphae. It is concluded that increased H⁺ effluxes of nodules resulted from enhanced nitrogenase activities induced by the presence of the AM fungus in lateral roots. The results point to additive effects of interactions between mycorrhizal fungi and rhizobia in increasing the extent of acidification of the “nodulesphere” and the hyposphere.     

Distinctive Mesorhizobium populations associated with Cicer arietinum L. in alkaline soils of Xinjiang, China

Background and aims

Rhizobia associated with chickpea in the main chickpea production zone of Xinjiang, China have never been investigated. Here, we present the first systematic investigation of these rhizobia’s genetic diversity and symbiotic interactions with their host plant.

Methods

Ninety-five isolates obtained from chickpea nodules in eight alkaline-saline (pH?8.24–8.45) sites in Xinjiang were characterized by nodulation test, symbiotic gene analysis, PCR-based restriction fragment length polymorphism (RFLP) of the 16S rRNA gene and 16S–23S rRNA intergenic spacer (IGS), BOX-PCR, phylogenies of 16S rRNA and housekeeping genes (atpD, recA and glnII), multilocus sequence analysis (MLSA) and DNA–DNA hybridization.

Results

All 95 isolates were identified within the genus of Mesorhizobium. Similarities less than 96.5% in MLSA and DNA–DNA hybridization values (<50%) between the new isolates and the defined Mesorhizobium species, and high similarities (>98%) of symbiotic genes (nodC and nifH) with those of the well studied chickpea microsymbioints Mesorhizobium ciceri and Mesorhizobium mediterraneum were found.

Conclusions

Chickpea rhizobia in alkaline-saline soils of Xinjiang, China, form a population distinct from the defined Mesorhizobium species. All these chickpea rhizobia in Xinjiang harbored symbiotic genes highly similar to the type strains of two well-studied chickpea rhizobia, M. ciceri and M. mediterraneum, evidencing the possible lateral transfer of symbiotic genes among these different rhizobial species. On the other hand, chickpea may strongly select rhizobia with a unique symbiotic gene background.     

Generation of Fbn1 conditional null mice implicates the extracellular microfibrils in osteoprogenitor recruitment

Loss-of-function experiments in mice have yielded invaluable mechanistic insights into the pathogenesis of Marfan syndrome (MFS) and implicitly, into the multiple roles fibrillin-1 microfibrils play in the developing and adult organism. Unfortunately, neonatal death from aortic complications of mice lacking fibrillin-1 (Fbn1(-/-) mice) has limited the scope of these studies. Here, we report the creation of a conditional mutant allele (Fbn1(fneo) ) that contains loxP sites bordering exon1 of Fbn1 and an frt-flanked neo expression cassette downstream of it. Fbn1(fneo/+) mice were crossed with FLPeR mice and the resulting Fbn1(Lox/+) progeny were crossed with Fbn1(+/-) ;CMV-Cre mice to generate Fbn1(CMV-/-) mice, which were found to phenocopy the vascular abnormalities of Fbn1(-/-) mice. Furthermore, mating Fbn1(Lox/+) mice with Prx1-Cre or Osx-Cre mice revealed an unappreciated role of fibrillin-1 microfibrils in restricting osteoprogenitor cell recruitment. Fbn1(Lox/+) mice are, therefore, an informative genetic resource to further dissect MFS pathogenesis and the role of extracellular fibrillin-1 assemblies in organ development and homeostasis.     

Comparison of the functions of glutathionylspermidine synthetase/amidase from E. coli and its predicted homologues YgiC and YjfC

Protein function prediction is very important in establishing the roles of various proteins in bacteria; however, some proteins in the E. coli genome have their function assigned based on low percent sequence homology that does not provide reliable assignments. We have made an attempt to verify the prediction that E. coli genes ygiC and yjfC encode proteins with the same function as glutathionylspermidine synthetase/amidase (GspSA). GspSA is a bifunctional enzyme that catalyzes the ATP-dependent formation and hydrolysis of glutathionylspermidine (G-Sp), a conjugate of glutathione (GSH) and spermidine. YgiC and YjfC proteins show 51% identity between themselves and 28% identity to the synthetase domain of the GspSA enzyme. YgiC and YjfC proteins were expressed and purified, and the properties of GspSA, YgiC, and YjfC were compared. In contrast to GspSA, proteins YgiC and YjfC did not bind to G-Sp immobilized on the affinity matrix. We demonstrated that all three proteins (GspSA, YgiC and YjfC) catalyze the hydrolysis of ATP; however, YgiC and YjfC cannot synthesize G-Sp, GSH, or GSH intermediates. gsp, ygiC, and yjfC genes were eliminated from the E. coli genome to test the ability of mutant strains to synthesize G-Sp conjugate. E. coli cells deficient in GspSA do not produce G-Sp while synthesis of the conjugate is not affected in ΔygiC and ΔyjfC mutants. All together our results indicate that YgiC and YjfC are not glutathionylspermidine synthetases as predicted from the amino acid sequence analysis.     

Dynamic Changes of Lipopolysaccharide Levels in Different Phases of Acute on Chronic Hepatitis B Liver Failure

Background

High serum levels of lipopolysaccharide (LPS) with LPS-MD-2/TLR4 complex activated NF-kb and cytokine cause hepatic necrosis in animal models. We investigated the dynamic changes of LPS levels in patients with acute on chronic hepatitis B liver failure (ACHBLF).

Methods

We enrolled ACHBLF patients for a 12-week study. Patients’ LPS levels were measured along with 10 healthy controls. Patients on supportive care and recovered without intervention(s) were analyzed. Patients’ LPS levels during the disease progression phase, peak phase, and remission phase were compared with healthy controls.

Results

Among 30 patients enrolled, 25 who received interventions or expired during the study period were excluded from the analysis, five patients on supportive care who completed the study were analyzed. Significant abnormal distributions of LPS levels were observed in patients in different phases (0.0168±0.0101 in progression phase; 0.0960±0.0680 in peak phase; 0.0249±0.0365 in remission phase; and 0.0201±0.0146 in controls; respectively, p<0.05). The highest level of LPS was in the peak phase and significantly elevated when compared to controls (0.0201±0.0146 vs. 0.0960±0.0680, p = 0.007). There were no statistically significant differences in LPS levels between healthy controls and subjects in the progression phase or remission phase. Dynamic changes of LPS were correlated with MELD-Na in the progression phase (p = 0.01, R = 0.876) and in the peak phase (p = 0.000, R = −1.00).

Conclusions

Significant abnormal distributions of LPS levels were observed in ACHBLF with the highest level in the peak phase. The dynamic changes of LPS were correlated with disease severity and suggested LPS causing secondary hepatic injury.     

拟南芥过氧化物酶序列与功能的生物信息学分析

植物过氧化物酶(POD)属于多基因家族,不仅是植物体内清除活性氧自由基的重要酶类之一,而且参与多种生理生化过程,在维系植物生长发育过程中发挥重要的作用。采用生物信息学方法对拟南芥过氧化物酶家族的73个基因编码的蛋白质序列的结构和功能进行了分析,其中包含氨基酸的数量、等电点、跨膜结构域、信号肽、二级结构组成及磷酸化位点等,并用Mega4.0软件构建了去除信号肽前后的系统进化树,旨在了解其结构特征。对已经进行功能研究的成员进行结构分析,以此来揭示结构与功能之间的联系,为植物抵御氧化胁迫方面研究提供理论基础。     

Comprehensive Assessment of Milk Composition in Transgenic Cloned Cattle

The development of transgenic cloned animals offers new opportunities for agriculture, biomedicine and environmental science. Expressing recombinant proteins in dairy animals to alter their milk composition is considered beneficial for human health. However, relatively little is known about the expression profile of the proteins in milk derived from transgenic cloned animals. In this study, we compared the proteome and nutrient composition of the colostrum and mature milk from three lines of transgenic cloned (TC) cattle that specifically express human α-lactalbumin (TC-LA), lactoferrin (TC-LF) or lysozyme (TC-LZ) in the mammary gland with those from cloned non-transgenic (C) and conventionally bred normal animals (N). Protein expression profile identification was performed, 37 proteins were specifically expressed in the TC animals and 70 protein spots that were classified as 22 proteins with significantly altered expression levels in the TC and C groups compared to N group. Assessment of the relationship of the transgene effect and normal variability in the milk protein profiles in each group indicated that the variation in the endogenous protein profiles of the three TC groups was within the limit of natural variability. More than 50 parameters for the colostrum and mature milk were compared between each TC group and the N controls. The data revealed essentially similar profiles for all groups. This comprehensive study demonstrated that in TC cattle the mean values for the measured milk parameters were all within the normal range, suggesting that the expression of a transgene does not affect the composition of milk.