Phycobiliproteins: Molecular Structure, Production, Applications, and Prospects

Phycobiliproteins (PBPs) are the main component of light-harvesting complexes in cyanobacteria and red algae. In addition to their important role in photosynthesis, PBPs have many potential applications in foods, cosmetics, medical diagnosis and treatment of diseases. However, basic researches and technological innovations are urgently needed for exploring those potentials, such as structure and function, their biosynthesis as well as downstream purification. For medical use and application, mechanisms underlying their therapeutic effects must be elucidated. Focusing on these issues, this article gives a critical review on the current status on PBPs, including their structures and functions, preparation processes and applications. In addition, key technical challenges and possible solutions are prospected

糖尿病培训手册在培养糖尿病护士的应用

Objective: To explore the nursing service mode for specialized nurses in diabetes and its application effect. Methods:In view of the actual situation of our hospital, a special training manual named with Diabetes training manual was prior composed. 40 specialized nurses in diabetes were trained with the special training manual. Training lasted for 3 months. After the training, the specialized nurses were assessed with the specialty knowledge of Diabetes Mellitus, the skill of clinical procedures, and the knowledge about patients' health education. Results: The skill of the trained nurses was improved. The satisfaction of patients was enhanced.Conclusion: Diabetes training manual can be used for specialized nurses in diabetes.目的  探讨糖尿病护士培训方式。方法  对2013年1—10月本院内分泌科的40名糖尿病护士培训,根据以往医院的培训，结合本院实际，应用自编的糖尿病培训手册，最后考核糖尿病专科理论、操作及宣教能力考核，培训时间为3个月。结果  培训前与培训后比较差别有统计学意义（P＜0.05），理论、操作及健康宣教能力较培训前提高；提高了患者及新护士的满意度。结论  糖尿病培训手册可以用于培养糖尿病新护士

miR-182-5p Promotes Growth in Oral Squamous Cell Carcinoma by Inhibiting CAMK2N1

Background/Aims: Emerging evidence suggests that the propagation of oral squamous cell carcinoma (OSCC) is influenced by the abnormal expression of microRNAs (miRNAs). This study aimed to characterize the involvement of miR-182-5p in OSCC by targeting the calcium/ calmodulin-dependent protein kinase II inhibitor CAMK2N1. Methods: miR-182-5p expression was quantified in OSCC tissues and cell lines with reverse transcription polymerase chain reaction (RT-PCR). Cell colony formation, Cell Counting Kit-8 (CCK-8), Ki-67, and nude mouse xenograft assays were used to characterize the role of miR-182-5p in the proliferation of OSCC. A miR-182-5p target gene was identified with western blotting, RT-PCR, and luciferase activity assays. OSCC patient survival based on CAMK2N1 expression was also analyzed. Results: miR-182-5p was up-regulated in in vitro cell lines and in vivo clinical OSCC samples. CCK-8, colony formation, and Ki-67 assays revealed that miR-182-5p promoted the growth and proliferation of OSCC cells. miR-182-5p directly targeted CAMK2N1, as evidenced by luciferase assays and target prediction algorithms. CAMK2N1 operated as a tumor suppressor gene in patients with OSCC. Down-regulating miR-182-5p expression in the CAL-27 cell line restored CAMK2N1-mediated OSCC cell proliferation. miR-182-5p expression inhibited the activation of AKT, ERK1/2, and NF-κB. Mice injected with CAL-27 cells transfected with miR-182-5p-inhibitor demonstrated a significant increase in tumor size and weight and increased CAMK2N1 mRNA and protein expression compared with the miR-negative control group. Conclusion: The miR-182-5p-CAMK2N1 pathway can be potentially targeted to regulate the proliferation of OSCC cells

A predator-prey interaction between a marine Pseudoalteromonas sp. and Gram-positive bacteria

Predator-prey interactions play important roles in the cycling of marine organic matter. Here we show that a Gram-negative bacterium isolated from marine sediments (Pseudoalteromonas sp. strain CF6-2) can kill Gram-positive bacteria of diverse peptidoglycan (PG) chemotypes by secreting the metalloprotease pseudoalterin. Secretion of the enzyme requires a Type II secretion system. Pseudoalterin binds to the glycan strands of Gram positive bacterial PG and degrades the PG peptide chains, leading to cell death. The released nutrients, including PG-derived D-amino acids, can then be utilized by strain CF6-2 for growth. Pseudoalterin synthesis is induced by PG degradation products such as glycine and glycine-rich oligopeptides. Genes encoding putative pseudoalterin-like proteins are found in many other marine bacteria. This study reveals a new microbial interaction in the ocean

Lentiviral Transgenic MicroRNA-Based shRNA Suppressed Mouse Cytochromosome P450 3A (CYP3A) Expression in a Dose-Dependent and Inheritable Manner

Cytochomosome P450 enzymes (CYP) are heme-containing monooxygenases responsible for oxidative metabolism of many exogenous and endogenous compounds including drugs. The species difference of CYP limits the extent to which data obtained from animals can be translated to humans in pharmacodynamics or pharmacokinetics studies. Transgenic expression of human CYP in animals lacking or with largely reduced endogenous CYP counterparts is recognized as an ideal strategy to correct CYP species difference. CYP3A is the most abundant CYP subfamily both in human and mammals. In this study, we designed a microRNA-based shRNA (miR-shRNA) simultaneously targeting four members of mouse CYP3A subfamily (CYP3A11, CYP3A16, CYP3A41 and CYP3A44), and transgenic mice expressing the designed miR-shRNA were generated by lentiviral transgenesis. Results showed that the CYP3A expression level in transgenic mice was markedly reduced compared to that in wild type or unrelated miR-shRNA transgenic mice, and was inversely correlated to the miR-shRNA expression level. The CYP3A expression levels in transgenic offspring of different generations were also remarkably lower compared to those of controls, and moreover the inhibition rate of CYP3A expression remained comparable over generations. The ratio of the targeted CYP3A transcriptional levels was comparable between knockdown and control mice of the same gender as detected by RT-PCR DGGE analysis. These data suggested that transgenic miR-shRNA suppressed CYP3A expression in a dose-dependent and inheritable manner, and transcriptional levels of the targeted CYP3As were suppressed to a similar extent. The observed knockdown efficacy was further confirmed by enzymatic activity analysis, and data showed that CYP3A activities in transgenic mice were markedly reduced compared to those in wild-type or unrelated miR-shRNA transgenic controls (1.11±0.71 vs 5.85±1.74, 5.9±2.4; P<0.01). This work laid down a foundation to further knock down the remaining murine CYP3As or CYPs of other subfamilies, and a basis to generate CYP knockdown animals of other species

3,6-Anhydro-L-Galactose Dehydrogenase VvAHGD is a member of a new aldehyde dehydrogenase family and catalyzes by a novel mechanism with conformational switch of two catalytic residues Cysteine 282 and Glutamate 248

3,6-anhydro-α-L-galactose (L-AHG) is one of the main monosaccharide constituents of red macroalgae. In the recently discovered bacterial L-AHG catabolic pathway, L-AHG is first oxidized by a NAD(P)+-dependent dehydrogenase (AHGD), which is a key step of this pathway. However, the catalytic mechanism(s) of AHGDs is still unclear. Here, we identified and characterized an AHGD from marine bacterium Vibrio variabilis JCM 19239 (VvAHGD). The NADP+-dependent VvAHGD could efficiently oxidize L-AHG. Phylogenetic analysis suggested that VvAHGD and its homologs represent a new aldehyde dehydrogenase (ALDH) family with different substrate preferences from reported ALDH families, named the L-AHGDH family. To explain the catalytic mechanism of VvAHGD, we solved the structures of VvAHGD in the apo form and complex with NADP+ and modeled its structure with L-AHG. Based on structural, mutational, and biochemical analyses, the cofactor channel and the substrate channel of VvAHGD are identified, and the key residues involved in the binding of NADP+ and L-AHG and the catalysis are revealed. VvAHGD performs catalysis by controlling the consecutive connection and interruption of the cofactor channel and the substrate channel via the conformational changes of its two catalytic residues Cys282 and Glu248. Comparative analyses of structures and enzyme kinetics revealed that differences in the substrate channels (in shape, size, electrostatic surface, and residue composition) lead to the different substrate preferences of VvAHGD from other ALDHs. This study on VvAHGD sheds light on the diversified catalytic mechanisms and evolution of NAD(P)+-dependent ALDHs

Structure of Vibrio collagenase VhaC provides insight into the mechanism of bacterial collagenolysis

The collagenases of Vibrio species, many of which are pathogens, have been regarded as an important virulence factor. However, there is little information on the structure and collagenolytic mechanism of Vibrio collagenase. Here, we report the crystal structure of the collagenase module (CM) of Vibrio collagenase VhaC and the conformation of VhaC in solution. Structural and biochemical analyses and molecular dynamics studies reveal that triple-helical collagen is initially recognized by the activator domain, followed by subsequent cleavage by the peptidase domain along with the closing movement of CM. This is different from the peptidolytic mode or the proposed collagenolysis of Clostridium collagenase. We propose a model for the integrated collagenolytic mechanism of VhaC, integrating the functions of VhaC accessory domains and its collagen degradation pattern. This study provides insight into the mechanism of bacterial collagenolysis and helps in structure-based drug design targeting of the Vibrio collagenase