Roles of H2S and NO in regulating the antioxidant system of Vibrio alginolyticus under norfloxacin stress

Antioxidant system is of great importance for organisms to regulate the level of excessive reactive oxygen species (ROS) under the environmental stresses including antibiotics stress. Effects of norfloxacin (NOR) on cystathionine-β-synthase (CBS), nitric oxide synthase (NOS) and antioxidant enzymes were investigated, and interaction between NO and H2S and their regulation on the antioxidant system of Vibrio alginolyticus under NOR were determined as well in the present study. After treated with 2 µg/mL NOR (1/2 MIC), CBS content, H2S and NO contents decreased while H2O2 accumulation and the antioxidant-related genes mRNA level increased. Additionally, the endogenous H2S content in V. alginolyticus was increased by the exogenous NO, while H2O2 accumulation and the relative expression level of SOD (Superoxide dismutase gene) decreased under exogenous NO or H2S. And the content of endogenous NO and NOS in V. alginolyticus increased under the exogenous H2S as well. Taken together, these results showed that anti-oxidative ability in V. alginolyticus was respectively enhanced by the gas molecules of H2S and NO under NOR-induced stress, and there may be a crosstalk regulative mechanism between H2S and NO. These results lay a foundation for the research of regulation network of H2S and NO, and provide a hint to synthesize anti-vibrio drugs in the future.

The Effects and Regulative Mechanism of Scutellaria Baicalensis Georgi Stems and Leaves Flavonoids in Promoting Neurogenesis and Improving Memory Impairment Mediated by BDNF-ERK-CREB Signal Pathway in Rats

Background: It is well known that Alzheimer's disease (AD) is a degenerative disease, and accompanied by memory impairment and main pathological changes of the extracellular senile plaque (SP) and intracellular neurofibrillary tangles (NFTs). However, there are many evidences showing that the disorders of neurogenesis are also regarded as a new opinion in AD. Objective: To investigate the effects and regulative mechanism of Scutellaria baicalensis Georgi stems and leaves flavonoids in promoting neurogenesis and improving memory impairment mediated by BDNF-ERK-CREB signal pathway in rats. Methods: Male Wistar rats were intracerebroventricularly injected with amyloid-beta protein 25-35 (Aβ25-35) in combination with aluminum trichloride (AlCl3) and recombinant human transforming growth factor-β1 (RHTGF-β1) (composited Aβ), to establish an AD model. Morris water maze was used to screen AD model of rats and measure the rats’ learning and memory ability. The expression of cell neurogenesis related molecule Ki67 protein in the hippocampal gyrus of rats was detected by the immunohistochemical method. The expression of mRNA and protein of Grb2, SOS1, Ras, ERK and BDNF in the BDNF-ERK-CREB signaling pathway, in the hippocampus and cerebral cortex were assayed by the Quantitative real-time PCR (qPCR) and Western blotting methods, respectively. Results: Intracerebroventricular injection of composited Aβ could produce the rats’ memory impairment, decrease the protein expression of Ki67 in the hippocampal gyrus, and increase the mRNA and protein expression levels of Grb2, SOS1, Ras, ERK and BDNF in the hippocampus and cerebral cortex. However, SSF could significantly ameliorate the rats’ memory impairment, lower the reduction of Ki67 protein expression in the hippocampal gyrus and regulate the mRNA and protein expression abnormal levels of Grb2, SOS1, Ras, ERK and BDNF in the hippocampus and cerebral cortex induced by composited Aβ. Conclusion: Composited Aβ can result in memory impairment, decrease neurogenesis and regulate the mRNA and protein abnormal expression of Grb2, SOS1, Ras, ERK and BDNF in BDNF-ERK-CREB signaling pathway. The effects of SSF in promoting neurogenesis and improving memory impairment may be related to the regulation in Grb2, SOS1, Ras, ERK and BDNF molecules’ expression of the BDNF-ERK-CREB signaling pathway.

The role of Clt1-regulated-Xylan metabolism in the melanin and toxin formation for the pathogenicity of Curvularia lunata in Maize

We previously reported that the BTB domain-containing protein Clt1 regulates melanin and toxin synthesis, conidiation, and pathogenicity in Curvularia lunata, but the interacting proteins and regulative mechanism of Clt1 are unclear. In this research, we identified two proteins, which respectively correspond to xylanase (Clxyn24) and acetyl xylan esterase (Claxe43) from C. lunata were regulated by Clt1. Yeast two-hybrid (Y2H), and bimolecular fluorescence complementation assays were conducted to verify the interaction of Clt1 with full-length Clxyn24 and Claxe43. Furthermore, the Y2H assay revealed that Clt1 physically interacted with Clxyn24 and Claxe43 through its BTB domain to degrade xylan which was used as a carbon source for C. lunata growth. The utilization of xylan provides acetyl-CoA for the synthesis of melanin and toxin, as well as energy and other intermediate metabolites for conidiation. Furthermore, transcriptome analysis revealed that PKS18 and its 13 flanking genes are found clustered in a region spanning 57.89 kb on scaffold 9 of the C. lunata CX-3 genome were down-regulated in toxin production deficient mutant T806, and this cluster is possibly responsible for toxin biosynthesis of C. lunata.

Flavonoids from Stem and Leaf of Scutellaria Baicalonsis Georgi Inhibit the Phosphorylation on Multi-sites of Tau Protein Induced by Okadaic Acid and the Regulative Mechanism of Protein Kinases in Rats

Aim: The aim of the present study is to investigate the effect of flavonoids from stem and leaf of Scutellaria baicalonsis Georgi (SSF) on multi-sites phosphorylation of tau protein in cerebral cortex and hippocampus of rats induced by okadaic acid (OA) and the regulative mechanism of the protein kinases. Methods: The model of AD-like memory impairment and neuronal injuries was established in male SD rats who were microinjected with OA (200 ng/kg) to establish a memory impairment model and screened for successful model rats by Morris water maze on day 21 after surgery. The successful model rats were continuously administered with intragastric infusion (ig) SSF 25, 50, and 100 mg/kg or Ginkgo biloba leaves flavonoids (GLF) 200 mg/kg for 36 d. The relative protein expressed levels of phosphorylated tau protein at sites of Ser199, Ser202, Ser214, Ser404 and Thr231, protein kinases (CDK5, PKA, pTyr216-GSK3β and pSer9-GSK3β) were detected by Western blotting. Results: The relative protein expressed levels of p-tau(Ser199), p-tau(Ser202), p-tau(Ser214), p-tau(Ser404) p-tau(Thr231), and pTyr216-GSK3β were significantly increased in both cerebral cortex and hippocampus regions of the model rats subjected to intracerebroventricular injection of OA (P<0.01), while the protein expressed levels of CDK5, PKA and pSer9- GSK3β (P<0.01) were reduced. SSF can dramatically reverse these increments in phosphorylated tau protein levels (P<0.01) and differently regulate the protein expressed levels of CDK5, PKA, and GSK3β (P<0.01) in rats’ cerebral cortex and hippocampus induced by OA. GLF also exhibits a similar effect on SSF. Conclusion: The results demonstrated that SSF could inhibit the hyperphosphorylation of tau in rats’ cerebral cortex and hippocampus induced by microinjection of OA, which may be related to the activities of protein kinase CDK5, PKA, and GSK3β.

Meeting up for management control: bracketing interaction in innovation development

PurposeThe purpose of this paper is to examine meetings as a form of meta-practice and investigate their role related to management control of innovation development.Design/methodology/approachThis research draws on case studies of two biotechnology firms operating in pharmaceuticals and medicine, which represent different contexts regarding the uncertainty and complexity of innovation development.FindingsThe study suggests two distinct roles of meetings in the context of innovation development: meetings as regulating and ordering; and meetings as a resource. In the first role, meetings serve as a regulative mechanism that brings together multiple elements of control into a system. Meetings as a meta-practice regulate and order by bracketing elements of innovation in time and space, rendering the innovation process more manageable and allowing actors to handle the complexity of knowledge. In the second role, meetings are used as a resource, sporadically intervening in the ongoing activities of innovation projects. The study explains how these two roles relate to the uncertainty and complexity of innovation development and have different implications for management control.Originality/valueThe study challenges the instrumental view of meetings by taking a closer look at their structuring potential in the organization. Understanding the roles of meetings provides another perspective on the functioning of management control and opens new avenues for studying the practices of control and decision-making.

Flexibility-Rigidity Coordination of the Dense Exopolysaccharide Matrix in Terrestrial Cyanobacteria Acclimated to Periodic Desiccation

ABSTRACT A dense exopolysaccharide (EPS) matrix is crucial for cyanobacterial survival in terrestrial xeric environments, in which cyanobacteria undergo frequent expansion and shrinkage processes during environmental desiccation-rehydration cycles. However, it is unclear how terrestrial cyanobacteria coordinate the structural dynamics of the EPS matrix upon expansion and shrinkage to avoid potential mechanical stress while benefiting from the matrix. In the present study, we sought to answer this question by investigating the gene expression, protein dynamics, enzymatic characteristics, and biological roles of WspA, an abundantly secreted protein, in the representative terrestrial cyanobacterium Nostoc flagelliforme. The results demonstrated that WspA is a novel β-galactosidase that facilitates softening of the EPS matrix by breaking the polysaccharide backbone under substantial moisture or facilitates the thickening and relinkage of the broken matrix during the drying process, and thus these regulations are well correlated with moisture availability or desiccation-rehydration cycles. This coordination of flexibility and rigidity of the cyanobacterial extracellular matrix may contribute to a favorable balance of cell growth and stress resistance in xeric environments. IMPORTANCE How the exopolysaccharide matrix is dynamically coordinated by exoproteins to cope with frequent expansion and shrinkage processes in terrestrial colonial cyanobacteria remains unclear. Here we elucidated the biochemical identity and biological roles of a dominant exoprotein in these regulation processes. Our study thus gained insight into this regulative mechanism in cyanobacteria to combat periodic desiccation. In addition, the filamentous drought-adapted cyanobacterium Nostoc flagelliforme serves as an ideal model for us to explore this issue in this study.

MOKESČIŲ REGULIACINIO MECHANIZMO ANALIZĖ

Straipsnyje analizuojama mokesčių teisės reguliacinė funkcija, jos poveikio mechanizmas, tiriami ir analizuojami mokesčių teisės reguliacinės funkcijos ypatumai. Siekdamas atskleisti svarbiausius mokesčių teisės reguliacinės funkcijos požymius, autorius mokesčių teisės reguliacinį mechanizmą ir jo poveikį analizuoja lygindamas jį su tradicine pozityviosios teisės metodologija pagrįsta teisinio reguliavimo samprata. Straipsnyje daug dėmesio skiriama mokesčių reguliacinės funkcijos fiskaliniam (ekonominiam) turiniui. The article analyses regulative function and regulative mechanism of the tax law. The article focuses on the analysis of the features of the regulative tax function and its regulative impact. The features of the regulative tax function are analyzed in comparison with legal regulation based on the methodology of traditional positivism. Also the article focuses on the strong economical content of the regulative tax function.

MP Modelling of Glucose-Insulin Interactions in the Intravenous Glucose Tolerance Test

The Intravenous Glucose Tolerance Test is an experimental procedure used to study the glucose-insulin endocrine regulatory system. An open problem is to construct a model representing simultaneously the entire regulative mechanism. In the past three decades, several models have appeared, but they have not escaped criticisms and drawbacks. In this paper, the authors apply the Metabolic P systems theory for developing new physiologically based models of the glucose-insulin system, which can be applied to the IVGTT. Ten data-sets obtained from literature were considered and an MP model was found for each, which fits the data and explains the regulations of the dynamics. Finally, each model is analysed to define a common pattern which explains, in general, the action of the glucose-insulin control system.