Berberine Could Ameliorate Cardiac Dysfunction via Interfering Myocardial Lipidomic Profiles in the Rat Model of Diabetic Cardiomyopathy

Background: Diabetic cardiomyopathy (DCM) is considered to be a distinct clinical entity independent of concomitant macro- and microvascular disorders, which is initiated partly by disturbances in energy substrates. This study was to observe the dynamic modulations of berberine in DCM rats and explore the changes of lipidomic profiles of myocardial tissue.Methods: Sprague-Dawley (SD) rats were fed high-sucrose and high-fat diet (HSHFD) for totally 22 weeks and intraperitoneally (i.p.) injected with 30 mg/kg of streptozotocin (STZ) at the fifth week to induce DCM. Seventy-two hours after STZ injection, the rats were orally given with berberine at 10, 30 mg/kg and metformin at 200 mg/kg, respectively. Dynamic changes of cardiac function, heart mass ratios and blood lipids were observed at f 4, 10, 16, and 22, respectively. Furthermore, lipid metabolites in myocardial tissue at week 16 were profiled by the ultra-high-performance liquid chromatography coupled to a quadruple time of flight mass spectrometer (UPLC/Q-TOF/MS) approach.Results: Berberine could protect against cardiac diastolic and systolic dysfunctions, as well as cardiac hypertrophy, and the most effective duration is with 16-week of administration. Meanwhile, 17 potential biomarkers of phosphatidylcholines (PCs), phosphatidylethanolamines (PEs) and sphingolipids (SMs) of DCM induced by HSFD/STZ were identified. The perturbations of lipidomic profiles could be partly reversed with berberine intervention, i.e., PC (16:0/20:4), PC (18:2/0:0), PC (18:0/18:2), PC (18:0/22:5), PC (20:4/0:0), PC (20:4/18:0), PC (20:4/18:1), PC (20:4/20:2), PE (18:2/0:0), and SM (d18:0/16:0).Conclusions: These results indicated a close relationship between PCs, PEs and SMs and cardiac damage mechanisms during development of DCM. The therapeutic effects of berberine on DCM are partly caused by interferences with PCs, PEs, and SMs metabolisms

Analysis of the Metabolic Characteristics of Serum Samples in Patients With Multiple Myeloma

Aims: This study aimed to identify potential, non-invasive biomarkers for diagnosis and monitoring of the progress in multiple myeloma (MM) patients.Methods: MM patients and age-matched healthy controls (HC) were recruited in Discovery phase and Validation phase, respectively. MM patients were segregated into active group (AG) and responding group (RG). Serum samples were collected were conducted to non-targeted metabolomics analyses. Metabolites which were significantly changed (SCMs) among groups were identified in Discovery phase and was validated in Validation phase. The signaling pathways of these SCMs were enriched. The ability of SCMs to discriminate among groups in Validation phase was analyzed through receiver operating characteristic curve. The correlations between SCMs and clinical features, between SCMs and survival period of MM patients were analyzed.Results: Total of 23 SCMs were identified in AG compared with HC both in Discovery phase and Validation phase. Those SCMs were significantly enriched in arginine and proline metabolism and glycerophospholipid metabolism. 4 SCMs had the discriminatory ability between MM patients and healthy controls in Validation phase. Moreover, 12 SCMs had the ability to discriminate between the AG patients and RG patients in Validation phase. 10 out of 12 SCMs correlated with advanced features of MM. Moreover, 8 out of 12 SCMs had the negative impact on the survival of MM. 5′-Methylthioadenosine may be the only independent prognostic factor in survival period of MM.Conclusion: 10 SCMs identified in our study, which correlated with advanced features of MM, could be potential, novel, non-invasive biomarkers for active disease in MM

Co‐evolutionary adaptations of Acinetobacter baumannii and a clinical carbapenemase‐encoding plasmid during carbapenem exposure

Abstract: OXA‐23 is the predominant carbapenemase in carbapenem‐resistant Acinetobacter baumannii. The co‐evolutionary dynamics of A. baumannii and OXA‐23‐encoding plasmids are poorly understood. Here, we transformed A. baumannii ATCC 17978 with pAZJ221, a blaOXA−23‐containing plasmid from clinical A. baumannii isolate A221, and subjected the transformant to experimental evolution in the presence of a sub‐inhibitory concentration of imipenem for nearly 400 generations. We used population sequencing to track genetic changes at six time points and evaluated phenotypic changes. Increased fitness of evolving populations, temporary duplication of blaOXA−23 in pAZJ221, interfering allele dynamics, and chromosomal locus‐level parallelism were observed. To characterize genotype‐to‐phenotype associations, we focused on six mutations in parallel targets predicted to affect small RNAs and a cyclic dimeric (3′ → 5′) GMP‐metabolizing protein. Six isogenic mutants with or without pAZJ221 were engineered to test for the effects of these mutations on fitness costs and plasmid kinetics, and the evolved plasmid containing two copies of blaOXA−23 was transferred to ancestral ATCC 17978. Five of the six mutations contributed to improved fitness in the presence of pAZJ221 under imipenem pressure, and all but one of them impaired plasmid conjugation ability. The duplication of blaOXA−23 increased host fitness under carbapenem pressure but imposed a burden on the host in antibiotic‐free media relative to the ancestral pAZJ221. Overall, our study provides a framework for the co‐evolution of A. baumannii and a clinical blaOXA−23‐containing plasmid in the presence of imipenem, involving early blaOXA−23 duplication followed by chromosomal adaptations that improved the fitness of plasmid‐carrying cells

Development of a High-Throughput, Growth-Based Selection Platform to Obtain NMN-Dependent Biocatalysts through Directed Evolution

Noncanonical redox cofactors, or cofactor mimics, which operate in an orthogonal manner to the natural counterpart nicotinamide adenine dinucleotide (phosphate), NAD(P)+, in the cells, are considered promising tools to increase the specificity and decrease the cost of biomanufacturing. While the reversing of enzymatic nicotinamide-based coenzyme specificity of all NAD(P)-utilizing enzymes has become a mature technology, shifting enzymes’ cofactor preferences towards noncanonical redox cofactors remains a challenging task. In this work, we demonstrated the development and application of growth-based, high-throughput selection platforms based on redox balance. These selection platforms enable generic and efficient engineering of NMN(H)-dependent enzymes through directed evolution.First, we developed a selection platform based on the NADPH-dependent redox balance to elucidate the relationship between the redox balance principle and the growth of Escherichia coli (E. coli). In this part, we switched the cofactor preference of glycolysis by introducing a heterologous NADPH-generating glyceraldehyde-3-phosphate dehydrogenase (GapDH) into a gapA deficient E. coli strain. The growth of the resulting strain specifically depended on the heterologously-introduced NADPH-oxidizing reactions under anaerobic condition, and automatically eliminated nonfunctional variants. This part of work served as a proof of concept, and we applied this principle for having extensive application in the directed evolution of NMN(H)-dependent redox enzymes. Next, we attempted to engineer redox enzymes to favor NMN+ under the guidance of computational simulation. After three rounds of rational design, we engineered glucose dehydrogenase (GDH) from Bacillus megaterium to specifically reduce nicotinamide mononucleotide (NMN+) using glucose. The resultant mutant (GDH Ortho) had an overall specificity switch of ~2 × 107- and ~1 × 107-fold toward NMN+ from NAD+ and NADP+, respectively, based on apparent kinetic parameters. The activity of GDH Ortho can be linked to the growth rate of cells by introducing the GDH Ortho along with the Entner–Doudoroff pathway (ED pathway) into strain lacking the Embden–Meyerhof–Parnas (EMP) pathway and pentose phosphate pathway (PPP). The resulting strain allowed us to develop a high-throughput selection method for obtaining NMN+-dependent enzymes through directed evolution. Moreover, as many redox enzymes share key structural features, the engineering strategy in GDH Ortho may be adopted to devise additional NMN(H)-dependent redox enzymes. Finally, we utilized our experience in NMN-dependent protein engineering and redox balance-based selection construction to develop an efficient selection method to obtain NMN(H)-dependent enzymes. In this selection platform, a life-essential enzyme, glutathione reductase (Gor) was engineered to specifically require the noncanonical reducing power through NMNH. This enzyme links thiol-disulfide balance-dependent cell growth and the intracellular NMNH level, which enables the selection of NMN+ reducing enzymes in directed evolution. After optimization and characterization, the selection platform was applied to engineer an efficient NMNH-generation phosphite dehydrogenase (TS-PTDH), which is a widely used enzyme for reducing power generation in industrial bioprocesses. Compared with wild type TS-PTDH, the best mutant A155N-E175A-A176F obtained from selection exhibited about 146-fold higher apparent catalytic efficiency (kcat / Km) when using NMN+ as the cofactor. Combined with computational library design, this selection platform will allow the broader bioengineering community to make their own NMN(H)-utilizing enzymes in a streamlined fashion

Effects of emergent vegetation on open channel flow

The presence of vegetation in an open channel has significant influences on hydrodynamic characteristics such as velocity distribution, flow discharge and turbulence structures, making the situation become much more complex than usual cases. Experiments and studies were carried out in CEE Hydraulics Lab, NTU, to explore the effect of emergent vegetation on open channel flow. In the flume experiments, two kinds of vegetation models were tested in the condition of uniform flow with five different flume bed slopes. Electromagnetic Current Meter (EMCM) was used to measure the flow velocity at a specific location. By analyzing four main parameters, velocity distribution, flow discharge, Manning’s roughness coefficient and turbulence structure, the effects of emergent vegetation on uniform open channel flow are identified.Bachelor of Engineering (Environmental Engineering

The Effects of the Global Financial Crisis on China's Financial Market and Macroeconomy

This paper provides a brief review of the increasing importance of China in the world economy and discusses the spillover effects of the global financial crisis on China's financial markets and macroeconomy. It presents and critiques alternative ways of estimating these effects. Contrary to much popular discussion, China was hit fairly hard by the global recession generated by the financial crisis. It suffered a huge drop in exports, and these effects on the economy were only partially offset by China's huge stimulus program. While growth remained well above international averages, its drop was of the same order of magnitude as for the United States. The paper closes with a brief discussion of some of the major challenges facing China to rebalance its economy in order to sustain high growth