Effects of Corticosterone, cAMP, cGMP, Ca^(2+), and Protein Kinase C on Apoptosis of Mouse Thymocytes Induced by X-ray Irradiation

Objective To observe the effects of signal factors of corticosterone （CS）, cAMP, cGMP, Ca^2＋ and protein kinase C （PKC） on lymphocyte apoptosis in mouse thymus induced by X-rays of 4 Gy in vitro. Methods The DNA lyric rate for thymocytes was measured by fluomspectrophotometry. Results The DNA lyric rate for thymocytes 4-8 hours after irradiation with 2-8 Gy was significantly higher than that in the control （P〈0.01）. As compared with the control, the DNA lyric rate for thymocytes treated with 0.01 μnol/L CS （P〈0.01）, 50 ng/mL cAMP （P〈0.01）, 0.05-0.4 μg/mL ionomycin （Iono, P〈0.05 or P〈0.01） or 0.05-0.4 ng/mL phorbol myristate acetate （PMA, P〈0.05 or P〈0.01）, respectively, was significantly increased, while the rate for thymocytes treated with 50 ng/mL cGMP was not significantly increased. The DNA lyric rate for thymocytes treated with 0.01 μmol/L CS （P〈0.01）, 50 ng/mL cAMP （P〈0.01）, 0.2 and 0.4 μg/mL Iono （P〈0.05）, and 0.2 and 0.4 ng/mL PMA （P〈0.05） plus 4-Gy irradiation, respectively, was significantly higher than that treated with single 4-Gy irradiation, while the rate for thymocytes treated with 50 ng/mL cGMP plus 4-Gy irradiation was not increased. When both 0.4 I.tg/mL Iono and 0.4 ng/mL PMA acted on the thymocytes, the DNA lyric rate for thymocytes was significantly higher than that in the control （P〈0.01）, the DNA lytic rate for thymocytes treated with both 0.4 μg/mL Iono and 0.4 ng/mL PMA plus 4-Gy irradiation was significantly higher than that treated with single 4-Gy irradiation （P〈0.05）, but was Iono plus 4-Gy irradiation or 0.4 ng/mL PMA plus 4-Gy irradiation. can promote thymocyte apoptosis induced by larger dose X-rays. not significantly higher than that treated with 0.4 μg/mL Conclusion CS, cAMP, Ca^2＋, and PKC signal factors can promote thymocyte apoptosis induced by larger dose X-rays.

Impacts of exercise interventions on different diseases and organ functions in mice

Background'. In recent years, much evidence has emerged to indicate that exercise can benefit people when performed properly. This reviewsummarizes the exercise interventions used in studies involving mice as they are related to special diseases or physiological status. To furtherunderstand the effects of exercise interventions in treating or preventing diseases, it is important to establish a template for exercise interventionsthat can be used in future exercise-related studies.Methods'. PubMed was used as the data resource for articles. To identify studies related to the effectiveness of exercise interventions for treatingvarious diseases and organ functions in mice, we used the following search language: (exercise [Title] OR training [Title] OR physical activity[Title]) AND (mice [title/abstract] OR mouse [title/abstract] OR mus [title/abstract]). To limit the range of search results, we included 2 filters:one that limited publication dates to "in 10 years,^ and one that sorted the results as "best match^^. Then we grouped the commonly used exercisemethods according to their similarities and differences. We then evaluated the effectiveness of the exercise interventions for their impact on diseasesand organ functions in 8 different systems.Results'. A total of 331 articles were included in the analysis procedure. The articles were then segmented into 8 systems for which the exerciseinterventions were used in targeting and treating disorders: motor system (60 studies), metabolic system (45 studies), cardio-cerebral vascularsystem (58 studies), nervous system (74 studies), immune system (32 studies), respiratory system (7 studies), digestive system (1 study), and thesystem related to the development of cancer (54 studies). The methods of exercise interventions mainly involved the use of treadmills, voluntarywheel-running, forced wheel-running, swimming, and resistance training. It was found that regardless of the specific exercise method used, mostof them demonstrated positive effects on various systemic diseases and organ functions. Most diseases were remitted with exercise regardless ofthe exercise method used, although some diseases showed the best remission effects when a specific method was used.Conclusion-. Our review strongly suggests that exercise intervention is a cornerstone in disease prevention and treatment in mice. Because exerciseinterventions in humans typically focus on chronic diseases, national fitness, and body weight loss, and typically have low intervention com・pliance rates, it is important to use mice models to investigate the molecular mechanisms underlying the health benefits from exerciseinterventions in humans.

Determination of Water Diffusion Coefficients and Dynamics in Adhesive/Carbon Fiber Reinforced Epoxy Resin Composite Joints

To determinate the water diffusion coefficients and dynamics in adhesive/carben fiber reinforced epoxy resin composite joints, energy dispersive X-ray spectroscopy analysis（EDX） is used to establish the content change of oxy- gen in the adhesive in adhesive/carbon fther reinforced epoxy resin composite joints. As water is made up of oxygen and hydrogen, the water diffusion coefficients and dynamics in adhesive/carben fiber reinforced epoxy resin composite joints can be obtained from the change in the content of oxygen in the adhesive during humidity aging, via EDX analy-sis. The authors have calculated the water diffusion coefficients and dynamics in the adhesive/carbon fiber reinforced epoxy resin composite joints with the aid of beth energy dispersive X-ray spectroscopy and elemental analysis. The de- termined results with EDX analysis are almost the same as those determined with elemental analysis and the results al- so show that the durability of the adhesive/carbon fther reinforced epoxy resin composite joints subjected to silane cou- pling agent treatment is better than those subjected to sand paper burnishing treatment and chemical oxidation treat- ment.

Expression Optimization and Characterization of the Catalytic Domain of Human MT3-MMP

Matrix metalloproteinases（MMPs） are a family of proteases that are required for many biological processes and are also elevated in many pathological conditions. MMP inhibitors （MMPIs） may therefore be useful as therapeutic agents in treating a number of diseases including cancer, cardiovascular diseases and arthritis. Attempts have been made to develop MMPIs. Recombinant MMPs have been used to screening MMPs in vitro assays. In this work, we report the expression of MMP-16 in E. coli and the characterization of the recombinant MMP-16 with a commonly used MMP substrate DQ-gelatin.

Synthesis of Cell Adhesive Motif RGD Tripeptide by a Novel Chemical Method and Its Purification

The cell adhesive motif RGD tripeptide was synthesized by using a novel chemical method. First, Gly-Asp（GD） was synthesized in two steps including the chloroacetylation of free L-aspartic acid and the ammonolysis of the chloroacetylated L-aspartic acid. The yield of chloroacetylated L-aspartic acid was 83.0%. For the ammonolysis of chloroacetylated L-aspartic acid, the yield of the ammonolyzed product was 92. 3%. Second, the coupling between Arg and Gly-Asp was carried out by using the NCA method. The maximum yield of RGD was about 50% at 0℃ and pH = 9. 5. The prepared RGD tripeptide was confirmed by using amino acid component analysis and mass spectrographic analysis.

Expression Characterization and Preparation of Human Amyloid Precursor Protein in Escherichia coli

To analyze whether expressed amyloid precursor protein（APP） existed in hydrophilic（cytoplasmid） or hydrophobic（lipid bilayer） environment in E. coli and to obtain intact APP for study on its function, we investigated the expression characterization and preparation of the three intact isoforms APP770, APP751, and APP695 in E. coll. The results show that these expressed APPs existed both in hydrophilic cytoplasm region as inclusion bodies and hydrophobic membrane region as membrane-bound state in E. coll. APPs in inclusion bodies were purified on an NTA-Ni^2＋ agarose column after dissolving in the urea buffer and APPs in membrane-bound state were obtained by ultracentrifugation. The activity analysis indicates that APP770 and APP751 exhibited strong trypsin-inhibitory activity like the natural ones. These results indicate that E. coli cells can be used as host cells for the expression of human integral membrane protein like APP in either soluble or membrane-bound state unless the interest protein undergone post-translational modification is required.

Catechu Inhibiting Cathepsin B Activity and Motility of HT1080 Cells

We reported that Catechu extract has a significant inhibitory effect on cathepsin B activity. The IC50 value for the Catechu extract against cathepsin B was 7.6 μg/mL. In addition, we showed that HT1080 human fibrosarcoma cells express cathepsin B and Catechu modulate the invasion and motility of these cells. These data may provide molecular mechanisms for the therapeutic effects of Catechu.

Monitoring the Hydrolysis of Olive Oil Catalyzed by Lipase via Acid Value Detection

Hydrolysis of olive oil catalyzed by Candida lipolytica lipase was investigated. The relative concentration of the components in the product was determined by using high performance liquid chromatography（HPLC）. Furthermore, a novel rapid method to detect the hydrolytic process of olive oil was developed based on the relationship between the acid value and the relative concentration of the different components.

Inhibition of Metalloproteinase Activity by Chinese Formulations Used to Treat Inflammatory Diseases

Matrix metalloproteinases （MMPs） are known to be involved in a number of pathological processes including cancer, atherosclerosis, arthritis and neurodegenerative disease among others. The drive to develop MMP inhibitors as therapeutics has been put forward for years by pharmaceutical companies as well as academicians. In an attempt to screen for MMP inhibitors from Traditional Chinese Medicines （TCMs） , a number of Chinese formulations used to treat inflammatory diseases such as nephritis and hepatitis have been studied. Strong inhibitory effects of three Chinese formulations toward the activity of MMP-16 have been discovered. These results suggest that these anti-inflammatory medicines contain some unknown MMP inhibitory compound（s） and provide reasonable molecular mechanisms for their theraoeutic effects.

Antioxidant Effect of Selenium-containing Glutathione S-Transferase in Rat Cardiomyocytes

As one of the most important antioxidant enzymes, glutathione peroxidase（GPX） protects cells and tissues from oxidative damage, and plays an important role in cardiovascular and cerebrovascular injuries induced by oxida- tive stress. The antioxidant effect of selenium-containing glutathione S-transferase（Se-GST）, a mimic of GPX was investigated on rat cardiomyocytes. To explore the protection function of Se-GST in hydrogen peroxide（H202） chal- lenged rat cardiomyocytes, we examined malondialdehyde（MDA）, lactate dehydrogenase（LDH）, superoxide dismu- tase（SOD） and cell apoptosis. The results demonstrate exposure of rat cardiomyocytes to H202 for 6 and 12 h induced the significant increases of MDA, LDH and apoptosis rate of cardiomyocytes, but pretreatment of rat cardiomyocytes with Se-GST at 0.0005 or 0.001 unit/mL prevents oxidative stress induced by H202 with the decreases of cell apopto- sis. All the results hint Se-GST has antioxidant activity for oxidative stress challenged rat cardiomyocvtes.

Chemoenzymatic Synthesis of Cellular Adhesion Tripeptide RGD Precursor in Organic Media

Chemoenzymatic synthesis of tripeptide Bz-RGD-（OEt）2 was conducted in this study. First, the free dipeptide Gly-Asp was synthesized via a novel chemical method, wherein only L-aspaxtic acid was used and was followed by the esterification of Gly-Asp. The formation of the linkage between the third amino acid Bz-Arg-OEt and Gly-Asp-（OEt）2 was completed by using the enzymatic method in organic media. The effects of several factors such as pH, the water content, triethylamine （TEA）, the molar ratio of the substrates, and the reaction time on the yield of Bz-RGD- （OEt）2 were examined. It was obtained that the optimum conditions for Bz-RGD-（OEt）2 synthesis in an ethanol/ Tris-HC1 buffer system （ volume ratio 93： 7 ） were as follows ： pH = 8.0 ; temperature, 30 ℃ ; reaction time, 7 h. The tripeptide yield was 75.2%.

Application of ring-opening metathesis polymerization in study of polymer molecular weight-mediated catalytic properties of immobilized lipase

Recently, significant efforts have been devoted into the study of the effect of hydrophobic supports on the catalytic properties of immobilized lipases. It seems that immobilization lipases on hydrophobic supports is a simple and efficient method to improve the catalytic activity of lipases. In this study, the hydrophobic poly(N-propyl-norbornene-exo-2,3-dicarboximide)s with well-controlled molecular weight were synthesized by the living ring-opening metathesis polymerization, and the lipases from Pseudo- monas sp. were then immobilized on these hydrophobic polymer supports through the physical ad- sorption. The immobilized lipases exhibited higher activity and enantioselectivity for the transesterifi- cation of 2-octanol than those of free lipases. Furthermore, we investigated the polymer molecular weight-mediated catalytic properties of immobilized lipases. It was found that the catalytic activity and E value of the immobilized lipases increased with the increase of the polymer molecular weight. At the polymeric molecular weight of about 40kDa, the highest E value (58 at 54.2% of conversion, enanti- omeric excess = 99%) was reached. After the molecular weight of polymers getting higher than 40 kDa, catalytic activity and E value of the immobilized lipase decreased.

Imprinted Human Serum Albumin with Antioxidant Activity

In order to create a new mimic of glutathione peroxidase（GPx）, bioimprinting was used to generate gluta-thione（GSH） binding site and chemical modification was used to incorporate catalytic group selenocystine（Sec）. Human serum albumin（HSA） and S-substituted dinitrophenyl glutathione（GSH-S-DNP） were chosen as the imprinted matrix and imprinting template, respectively, to generate a GSH-imprinted protein（GSH-HSA） by bioimprinting. Sec was incorporated into the GSH-HSA by chemical modification to give a new GPx mimic（Se-GSH-HSA）. Se-GSH-HSA displayed considerably higher GPx activity than non-printed HSA（Se-HSA）. The enzymic properties and kinetics of Se-GSH-HSA were studied. Moreover, Se-GSH-HSA was confirmed to have stronger antioxidant ability to protect mitochondria against oxidative damage with ferrous sulfate/ascorbate-induced mitochondria damage model, indicating that Se-GSH-HSA has potential application in medicine.

Impact of Stable Protein-protein Interaction on Protein Conformational Space

Backbone dihedral angle based clustering approach was applied to investigate the effect of protein complexation on backbone conformational space and the effect on protein dynamics. Three representative enzyme-inhibitor complexes and their comprised proteins were used as models for small- and moderate-sized globular proteins to compare available backbone conformational space before and after complexation. Microsecond time scale molecular dynamic simulations were generated to ensure sufficient statistics. The result suggests that stable protein-protein interactions lead to redistribution of protein backbone mobility and restriction of the protein backbone conformational space, especially for short time scale motions. Surprisingly, these effects are found to be uncorrelated with protein-protein interaction surface. Consistent with many experimental and computational observations, our results indicate that both induced-fit and conformational selection models play roles in stable protein complexation process, with the dominant role being different for different protein complexes.

Lipase-catalyzed Knoevenagel condensation between α,β-unsaturated aldehydes and active methylene compounds

A simple and efficient Knoevenagel condensation between a b-unsaturated aldehydes and active methylene compounds is reported.Notably,this condensation can be catalyzed by PPL（lipase from porcine pancreas） with satisfied yields（49%–92%）.Moreover,PPL induces moderate Z/E selectivity in the Knoevenagel condensation.