Dulbecco's Modified Eagle Medium Medium Research Articles

Testicular Cells Derived Conditioned Medium Supports Germ Cell Differentiation of Human Embryonic Stem Cells.

There are ethical and technical challenges in studying human germ cell development. Therefore, the aim of the study is in vitro differentiation of human embryonic stem cells (hESCs), as pluripotent cells, to the germ cells which is a valuable tool for studying molecular and cellular aspects of gametogenesis and understanding causes of infertility. In this experimental study, two different complete media [Dulbecco's Modified Eagle Medium (DMEM)+20% fetal bovine serum (FBS) and embryoid bodies (EBs) medium; KOSR/HES without basic fibroblast growth factor (bFGF)] were used in the both of test groups using testicular cells derived conditioned medium (TCCM) and control groups spontaneously differentiated (SD). Thereby, EBs from hESCs (Yazd2; 46XY) were cultured in different conditions EB medium; EB medium and conditioned EB medium; EB medium, DMEM, and FBS without conditioning; EB medium, conditioned DMEM, and FBS medium. EBs were collected after 4, 7, and 14 days and their gene expression profiles were assessed and compared to hESCs, as day 0, using IF and relative reverse transcription quantitative polymerase chain reaction (RT-qPCR). An increase in the gametogenesis gene expression level in TCCM groups was showed in comparison with SD groups. Additionally, immunostaining of differentiated cells in all groups showed in vitro gametogenesis (IVG). Our findings showed that human TCCM could be used as a natural niche for in vitro male and female germ cell development. However, further studies are needed to define the factors and metabolites within the human TCCM.

Fructo-oligosaccharide-mediated alteration in claudin expression in small intestinal absorptive Caco-2 cells is positively associated with the induction of inflammatory genes and the glucan receptor gene CLEC7A

ObjectivesIndigestible carbohydrates may strengthen tight junctions (TJs) independently of intestinal bacteria. This study investigated whether indigestible carbohydrates (i.e., fructo-oligosaccharides [FOS]) promote TJs directly to intestinal absorptive Caco-2 cells and examined the association between the expression of genes constructing TJs and other genes using mRNA microarray analysis. MethodsCaco-2 cells at 1.0 × 105/mL were seeded in a type I collagen plate and cultured in high-glucose Dulbecco's modified Eagle medium (DMEM) supplemented with 10% fetal calf serum (FCS); the cells reached confluence at 7 d after seeding. Ten days after the cells reached confluency, they were cultured for 24 h in 10% FCS-containing DMEM medium supplemented with 0%, 5%, or 10% FOS. We performed mRNA microarray to identify the genes whose expression was altered by FOS. Subsequently, quantitative reverse transcription polymerase chain reaction was performed for these altered genes, including CLEC7A encoding the glucan receptor, and for the claudin (CLDN) family genes. The expression of CLDN2, CLDN4, and CLEC7A proteins was assessed using western blot analysis. ResultsFOS decreased the mRNA and protein expression of CLDN2, which weakens TJs, and increased those of CLDN4, which strengthens TJs, in Caco-2 cells. FOS treatment (10%) reduced the mRNA expression of antioxidative genes and induced the expression of immune response–related genes, including CLEC7A, CCL2, and ITGA2. Furthermore, the expression of CLEC7A protein was enhanced by FOS. ConclusionsInduction of TJ-strengthening CLDN4 and reduction of TJ-weakening CLDN2 by FOS treatment in small intestinal absorptive Caco-2 cells is positively associated with the induction of inflammatory genes, including CLEC7A.

Effect of Fetal Bovine Serum Concentration towards Vero Cells Growth on Culture in DMEM Medium

Cell culture requires a suitable medium and environment for in vivo conditions. Conditions are created by regulating temperature, pH, oxygen, CO2, osmotic pressure, surfaces to adhere to cells, nutrients, and vitamins, protection against toxic substances, hormones, and growth factors that regulate cell growth and differentiation. In general, good cell growth occurs at a pH of 7.0 - 7.6. Fetal Bovine Serum (FBS) is one of the supplement media to support cell growth. The purpose of this study was to determine the effect of using FBS supplementation with various concentrations on vero cell culture media on DMEM (Dulbecco's modified eagle medium) media. Vero cell culture on DMEM media has been successfully carried out using FBS by observing its growth for 14 days. Vero cell culture process begins with the manufacture of media consisting of DMEM and FBS. The cell density of each well at 5% and 10% concentration media was 1017 cells/well. By varying the concentration of FBS in the culture medium, the difference in the number of cells produced can be observed under the microscope. The results showed that the number of Vero cells produced from DMEM media with 10% FBS concentration was higher than 5% FBS concentration. Thus, this study proves that the higher the concentration of FBS in the medium, the more it supports the cell growth process in the Vero cell culture process.

Selenium enhances the expression of miR-9, miR-124 and miR-29a during neural differentiation of bone marrow mesenchymal stem cells

BackgroundSelenium (Se) is a trace element that plays important role in antioxidant defense in the brain. Sodium selenite (Na2SeO3) is an inorganic salt of Se which has an antioxidant function. In the present study, we investigated the effect of Sodium selenite on the expression of important neuronal microRNAs during neural differentiation of bone marrow-derived stem cells (BMSCs). MethodsMesenchymal stem cells were collected from rat bone marrow and cultured in the Dulbecco's Modified Eagle Medium (DMEM) medium. 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay was conducted to determine the toxicity of Na2SeO3. For neural induction, BMSCs were divided into control, Na2SeO3 containing (10 ng/mL) and Na2SeO3 free groups and cultured in DMEM medium supplemented with Isobutyl-l-methylxanthine (IBMX), Fibroblast growth factor 2 (FGF2), B27, Retinoic acid, and brain derived neurotrophic factor (BDNF) for 14 days. At the end of the differentiation, immunostaining against Microtubule associated protein 2 (Map-2) and Choline acetyltransferase (ChAT) proteins was performed. Also, the total RNA is extracted from control and neural differentiated cells using a special kit, and the expression of miR-9, miR-124, and miR-29a was analyzed using real-time polymerase chain reaction (RT-PCR). ResultsIncreasing Na2SeO3 concentrations had increasing toxicity; therefore, the concentration of 10 ng/mL was used as a supplement during neural differentiation. Examination of the expression of Map-2 and ChAT proteins showed that Na2SeO3 increased the expression of them and consequently the neuronal differentiation of BMSCs. Na2SeO3 also significantly increased the expression of miR-9, miR-124, and miR-29a in BMSCs undergoing neuronal differentiation. ConclusionsOur results suggest that the protective effect of selenium on neural differentiation of stem cells may be mediated through neuron specific microRNAs. This result further highlights the importance of selenium supplementation in preventing neuronal diseases.

A dual responsive probe based on bromo substituted salicylhydrazone moiety for the colorimetric detection of Cd2+ ions and fluorometric detection of F‒ ions: Applications in live cell imaging

A dual responsive probe based on bromo substituted salicylhydrazone moiety for the colorimetric detection of Cd2+ ions and fluorometric detection of F‒ ions: Applications in live cell imaging

Modified DMEM xenic culture medium for propagation, isolation and maintenance of Balantioides coli

Balantioides coli is a known ciliated zoonotic protozoan that mainly causes diarrhea in humans and pigs. An efficient and reliable culture system for this parasite remains unavailable until now. In this study, a modified Dulbecco's modified eagle medium (DMEM) with pH 7.0–7.5, containing 5 mg/mL starch and 20% new calf serum, was optimized for propagation of B. coli at 28°C–32°C. At the growth-peaking stage, the average trophozoite density was up to 12,970 trophozoites per milliliter. A reproducible protocol for isolation and maintenance of this parasite was also developed based on the modified DMEM culture medium. Moreover, cloning results of B. colipopulations showed that 250 trophozoites in 3 mL modified DMEM medium were the minimal number of trophozoites that propagated to the growth-peaking stage, and finally obtained the individual population. However, less than 250 trophozoites failed to continuously grow in the modified DMEM culture medium under the optimal conditions for growth of B. coli. These data showed that the modified DMEM culture medium is an ideal and efficient medium for propagation and maintenance of B. coli in vitro and will help studies on its biology, genome, transcriptome, proteome, and drug screening.

Influence of human amniotic mesenchymal stem cells on macrophage phenotypes and inflammatory factors in full-thickness skin wounds of mice

Objective: To explore the influence of human amniotic mesenchymal stem cells (hAMSCs) on the in vivo and in vitro regulation of macrophage phenotypes and inflammatory factors associated with wound healing of full-thickness skin wounds in mice. Methods: Fresh amniotic membrane discarded from full-term delivery by 5 healthy pregnant women in the Department of Obstetrics and Gynecology of the Affiliated Hospital of Zunyi Medical University was used for the isolation and culture of hAMSCs by enzyme digestion method. The third passage of cells was used for identification of adipogenic and osteogenic differentiation. The fourth passage of cells was used for identification of hAMSCs surface markers. Ten C57BL/6 mice (all male, aged 6 to 8 weeks, the same gender and age below) were selected for extracting mouse peritoneal macrophages by intraperitoneal lavage, and M1-type macrophages were induced by Dulbecco's modified eagle medium (DMEM) medium containing interferon-γ. The M1-type macrophages were divided into hAMSCs+ macrophage group and macrophage alone group. Then 1×10(4) hAMSCs/per well of fourth passage were added to macrophage in hAMSCs+ macrophage group and cultured in 2 mL DMEM medium for routine culture. In macrophage alone group, each well was only added with 2 mL DMEM medium for routine culture. On day 1 and 7 in culture, the content of interleukin-12 (IL-12), arginase 1, and IL-10 in the cell culture supernatant of the 2 groups were detected by enzyme-linked immunosorbent assay with sample number of 6/per group. (2) Full-thickness skin wound model was reproduced in the back of 56 C57BL/6 mice, which were divided into hAMSCs group and phosphate buffer solution (PBS) group using the random number table, with 28 mice in each group. Mice in hAMSCs group were subcutaneously injected with 100 μL of cell suspension containing 1×10(7) hAMSCs per mL in PBS suspension along the wound edge. While mice in PBS group were only subcutaneously injected with 100 μL PBS along the wound edge. On post injection day (PID) 1, 3, 7, and 14, 7 mice in the two groups were sacrificed respectively. Histopathological observation was performed with hematoxylin-eosin staining. The expressions of macrophage surface markers [CD68 and inducible nitric oxide synthase (iNOS) double positive cells and CD68 and arginase 1 double positive] in the wounds were detected by immunofluorescent staining. The mRNA expressions of IL-10, macrophage inflammatory protein 1α (MIP-1α), and MIP-2 in the wounds were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were statistically analyzed with analysis of variance for factorial design, t test, and Bonferroni correction. Results: (1) On day 1 in culture, the content of IL-12 and arginase 1 in the cell culture supernatant of the two groups were similar (t=0.448, 0.536, P>0.05), and the content of IL-10 in the cell culture supernatant of hAMSCs+ macrophage group was significantly lower than that in macrophage alone group (t=14.722, P 0.05). On PID 3 and 7, the percentages of CD68 and iNOS double positive cells in the wounds in hAMSCs group were significantly lower than those of PBS group (t=6.396, 4.787, P 0.05). On PID 3, 7, and 14, the mRNA expressions of IL-10 in the wounds of mice in hAMSCs group were significantly higher than those of PBS group (t=7.758, 124.355, 80.823, P<0.01). On PID 1, 3, 7, and 14, the mRNA expressions of MIP-1α and MIP-2 in the wounds of mice in hAMSCs group (0.341±0.212, 0.648±0.004, 0.611±0.106, 0.763±0.049, 1.377±0.099, 1.841±0.042, 1.181±0.035, 0.553±0.028) were significantly lower than those of PBS group (3.853±0.035, 6.914±0.163, 3.648±0.113, 2.250±0.046, 11.119±0.495, 8.634±0.092, 5.722±0.021, 4.862±0.036, t=43.198, 101.904, 51.845, 58.231, 51.074, 177.501, 291.752, 251.614, P<0.01). Conclusions: hAMSCs demonstrates biological effects of promoting the transformation of M1-type macrophages into M2-type macrophages in full-thickness skin wounds of mice. They can up-regulate the expression of anti-inflammatory and anti-fibrotic factor IL-10, and down-regulate the expression of important inflammation mediated factors MIP-1α and MIP-2.

In vitro maintenance of Mansonella perstans microfilariae and its relevance for drug screening

BackgroundMansonellosis arises from infections with threadlike filarial nematodes in millions of individuals, especially in sub-Saharan Africa. Since infections present no overt clinical symptoms but attenuate immune responses that might lead to increased susceptibility and worsened disease course of concomitant infections, it is truly a neglected tropical disease. Nevertheless, only few studies focus on identifying suitable safe drugs for its control and little is known about the requirements for in vitro maintenance of the Mansonella perstans transmission stage. This study, therefore, evaluated the survival of M. perstans microfilariae (mf) using in vitro conditions that have been shown to promote survival of Loa loa, a closely related filarial nematode. Furthermore, the in vitro microfilaricidal effect of 15 agents was assessed on this helminth. MethodsThe ability of two basic culture media; Dulbecco's Modified Eagle's Medium (DMEM) and Roswell Park Memorial Institute (RPMI-1640) supplemented with 10% fetal bovine serum (FBS) and a monkey kidney epithelial cell line (LLC-MK2) to support the survival of M. perstans microfilariae was investigated. Subsequently, 6 anti-helminthics, 5 anti-malarials, 1 anti-microbacterial, 2 trypanocidals and 1 anti-cancer agent were tested in vitro against mf. The suitability of the culture media as well as the effect of the anti-infective agents on mf survival was assessed by scoring their motility. ResultsFBS supplement and additional LLC-MK2 cells significantly improved the survival of mf in DMEM and RPMI-1640 culture. In detail, RPMI-1640 supplemented with 10% FBS and LLC-MK2 cells sustained the maintenance of mf for at least 20 days (100.00 ± 0.00% survival). In co-cultures with LLC-MK2 cells without serum, M. perstans mf were maintained in DMEM and RPMI-1640 medium with a motility above 99% by day 5. Mefloquine displayed the highest microfilaricidal effect in vitro followed by artesunate. ConclusionBoth RPMI and DMEM in the presence of LLC-MK2 cells are suitable for the maintenance of M. perstans mf in vitro. In absence of the feeder cells, the addition of 10% FBS to RPMI-1640 medium improved the parasite survival rate and motility. The microfilaricidal activity of mefloquine and artesunate on M. perstans mf was documented for the first time in this study and can therefore be considered as reference for further screening of agents against this parasite stage.

The influence of culture media upon observed cell secretome metabolite profiles: The balance between cell viability and data interpretability

The application of metabolomics to investigating the cell secretome has garnered popularity owing to the method’s large-scale data output, biochemical insight, and prospects for novel target compound discovery. However, there are no standardized protocols for the use of cell growth media, a factor that can exert profound effects upon the detected metabolites, and thus in the interpretability of the resulting data. Herein, we applied a liquid chromatography-high resolution mass spectrometry-based metabolomics approach to examine the influence of 5 different media combinations upon the obtained secretome of two phenotypically different cell lines: human embryonic kidney cells (HEK293) and L6 rat muscle cells. These media combinations were, M1: Medium 199, M2: Medium 199 + 2% fetal bovine serum (FBS), M3: Dulbecco's Modified Eagle's Medium (DMEM), M4: DMEM + 2% FBS and M5: Krebs-Henseleit Modified Buffer (KHB). The effect of incubation (37 °C) vs. refrigeration (4 °C) on DMEM medium over a 24 h period was also investigated. Results were validated for a selected panel of 5 metabolites measured from an additional cell culture experiment. Metabolomics identified a total of 53 polar metabolites that exhibited differential patterns on a cell type- and medium-specific basis. We observed that choice of media was the primary contributor to the secreted metabolite profile detected. The addition of FBS resulted in unique detected metabolites, compared to media-only controls (M199 and DMEM alone). Glutamine and pyroglutamate were more abundant in incubated relative to refrigerated DMEM medium. The overall metabolic pattern of the metabolites from the targeted approach matched with that exhibited across M1-M5 of the metabolomics experiment, and aided in further identifying the presence of compounds that were below the limit of detection in metabolomics. Based upon these findings, we highlight the following considerations in designing a cell secretome-based metabolite profiling experiment: (1) multiple media combinations (with and without FBS) should be tested for each cell line to be investigated; (2) cell-free media combinations should be plated separately, and incubated/treated in the same experimental conditions as the cells; and (3) a compromise between cell death and metabolite detection should be identified in order to avoid batch-specific contributions from FBS supplementation.

Establishing elements of a synthetic biology platform for Vaccinia virus production: BioBrick™ design, serum-free virus production and microcarrier-based cultivation of CV-1 cells

Vaccinia virus (VACV) is an established vector for vaccination and is beginning to prove effective as an oncolytic agent. Industrial production of VACV stands to benefit in future from advances made by synthetic biology in genome engineering and standardisation. The CV-1 cell line can be used for VACV propagation and has been used extensively with the CRISPR/Cas9 system for making precise edits of the VACV genome. Here we take first steps toward establishing a scalable synthetic biology platform for VACV production with CV-1 cells featuring standardised biological tools and serum free cell cultivation. We propose a new BioBrick™ plasmid backbone format for inserting transgenes into VACV. We then test the performance of CV-1 cells in propagation of a conventional recombinant Lister strain VACV, VACVL-15 RFP, in a serum-free process. CV-1 cells grown in 5% foetal bovine serum (FBS) Dulbecco’s Modified Eagle Medium (DMEM) were adapted to growth in OptiPRO and VP-SFM brands of serum-free media. Specific growth rates of 0.047 h−1 and 0.044 h−1 were observed for cells adapted to OptiPRO and VP-SFM respectively, compared to 0.035 h−1 in 5% FBS DMEM. Cells adapted to OptiPRO and to 5% FBS DMEM achieved recovery ratios of over 96%, an indication of their robustness to cryopreservation. Cells adapted to VP-SFM showed a recovery ratio of 82%. Virus productivity in static culture, measured as plaque forming units (PFU) per propagator cell, was 75 PFU/cell for cells in 5% FBS DMEM. VP-SFM and OptiPRO adaptation increased VACV production to 150 PFU/cell and 350 PFU/cell respectively. Boosted PFU/cell from OptiPRO-adapted cells persisted when 5% FBS DMEM or OptiPRO medium was observed during the infection step and when titre was measured using cells adapted to 5% FBS DMEM or OptiPRO medium. Finally, OptiPRO-adapted CV-1 cells were successfully cultivated using Cytodex-1 microcarriers to inform future scale up studies.

Effect of hormones, follicular fluid, serum and media on in vitro maturation of porcine oocyte

The present study was conducted to evaluate the effect of hormones, follicular fluid, serum and media on in vitro maturation (IVM) of porcine oocyte. The procedures of IVM could be used for basic research purposes or commercial utilization. The IVM of oocyte is a critical step in in-vitro embryo production and it needs to be carried out in a precise manner under optimal conditions for subsequent fertilization and embryo development. For this purpose ovaries were collected from slaughtered pigs from an abattoir. Ovaries (1,232) were aspirated in 52 trials for IVM and fertilization for this study. Dulbecco Modified Eagle's medium (DMEM) or tissue culture medium (TCM-199) supplemented with gentamycin (50μl/ml), sodium pyruvate (100 mmol) and 10% serum, viz. estrus sow serum (ESS) or fetal calf serum (FCS) with or without porcine follicular fluid (PFF) and hormones such as pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (HCG) were used. The maturation was assessed by loosening of cumulus cells, enlargement of peri-viteline space or extrusion of first polar body and examination of metaphase II by aceto-orcein stain. The results revealed that DMEM with ESS yielded 53% while TCM+ESS yielded 45% maturation rates. The replacement of ESS with FCS resulted in 48.50 and 35.33% maturation in DMEM and TCM-199 medium, respectively. The addition of PFF in DMEM+ESS improved the maturation rate and was found better (74.55%) than TCM-199+ESS (65.35%). However, the replacement of ESS by FCS in either DMEM orTCM-199+PFF did not differ significantly. It can be concluded from the present study that use of DMEM+ESS+PFF along with hormones PMSG + luteinizing hormone (LH) for first 20-24 h followed by hormone free medium for next 20-22 h i.e. 42-44 h gave optimum (81.5%) in-vitro maturation rates in pigs. DMEM with ESS and PFF with hormone (PMSG/HCG) yielded highest maturation (81.50%) rate than TCM-199 with ESS, PFF and hormone (PMSG/HCG) which showed maturation rate of 76.59%.

A Two-Photon Excitation Based Fluorogenic Probe for Sialome Imaging in Living Systems.

Taking advantage of the fluorescence property of alkyne-modified naphthalimide, the two-photon excited fluorogenic probe Naph-yne is used for azide-tagged mannosyl glycoprotein imaging both at the cellular level and for vertebrate model organisms.

Functional Screen for Secreted Proteins by Monoclonal Antibody Library and Identification of Mac-2 Binding Protein (Mac-2BP) as a Potential Therapeutic Target and Biomarker for Lung Cancer

Identification of secreted proteins of lung cancer could provide new candidates of serum biomarkers for cancer diagnosis or targets for therapeutic intervention. In this study, we developed a novel strategy that combined functional monoclonal antibody library screening technique and mass spectrometry to identify functional secreted proteins. BALB/c mice were immunized with cancer cells isolated from fresh human lung cancer tissues. The monoclonal antibody library containing 1160 mAbs was established with the mouse spleen cells, whose serum had most anti-proliferative effect on lung cancer cells. Monoclonal antibodies were subjected to an immunoreactive and functional screen and monoclonal antibodies that reacted strongly with secreted proteins in condition medium and lung cancer tissues with high inhibotion of cell proliferation were selected. Antigens that recognized by antibodies were obtained by immunoprecipitation and then identified by mass spectrometry. Mac-2-binding protein (Mac-2BP), the antigen of 13H3 antibody, was identified using this approach. Functional studies demonstrated that the 13H3 antibody suppressed lung cancer cell lines ANIP-973 and A549 proliferation in vitro and inhibit ANIP973 xenograft tumors growth in vivo by inducing cell-cycle arrest at G1 phase, with up-regulation of p27 and down-regulation of cyclin D1. Moreover, the serum level of Mac-2BP was significantly higher in lung cancer patients than healthy controls. At a cutoff value of 6 μg/ml, Mac-2BP might be a diagnostic biomarker of lung cancer, especially for SCLC. Mac-2BP concentrations of 6 μg/ml or higher was associated with poor overall survival in univariate analysis, and was an independent predictor in the multivariate COX analysis. Together, these results firstly demonstrated that Mac-2BP can be used as a therapeutic target and potential biomarker for lung cancer. Our strategy is feasible, which may facilitate the identification of novel secreted biomarkers of lung cancer.

Quantitative Proteomic Analysis of Cellular Protein Modulation upon Inhibition of the NEDD8-Activating Enzyme by MLN4924

Cullin-RING ubiquitin ligases (CRLs) are responsible for the ubiquitination of many cellular proteins, thereby targeting them for proteasomal degradation. In most cases the substrates of the CRLs have not been identified, although many of those that are known have cancer relevance. MLN4924, an investigational small molecule that is a potent and selective inhibitor of the Nedd8-activating enzyme (NAE), is currently being explored in Phase I clinical trials. Inhibition of Nedd8-activating enzyme by MLN4924 prevents the conjugation of cullin proteins with NEDD8, resulting in inactivation of the entire family of CRLs. We have performed stable isotope labeling with amino acids in cell culture analysis of A375 melanoma cells treated with MLN4924 to identify new CRL substrates, confidently identifying and quantitating 5122-6012 proteins per time point. Proteins such as MLX, EID1, KLF5, ORC6L, MAGEA6, MORF4L2, MRFAP1, MORF4L1, and TAX1BP1 are rapidly stabilized by MLN4924, suggesting that they are novel CRL substrates. Proteins up-regulated at later times were also identified and siRNA against their corresponding genes were used to evaluate their influence on MLN4924-induced cell death. Thirty-eight proteins were identified as being particularly important for the cytotoxicity of MLN4924. Strikingly, these proteins had roles in cell cycle, DNA damage repair, and ubiquitin transfer. Therefore, the combination of RNAi with stable isotope labeling with amino acids in cell culture provides a paradigm for understanding the mechanism of action of novel agents affecting the ubiquitin proteasome system and a path to identifying mechanistic biomarkers.

Processivity and Subcellular Localization of Glycogen Synthase Depend on a Non-catalytic High Affinity Glycogen-binding Site

Glycogen synthase, a central enzyme in glucose metabolism, catalyzes the successive addition of α-1,4-linked glucose residues to the non-reducing end of a growing glycogen molecule. A non-catalytic glycogen-binding site, identified by x-ray crystallography on the surface of the glycogen synthase from the archaeon Pyrococcus abyssi, has been found to be functionally conserved in the eukaryotic enzymes. The disruption of this binding site in both the archaeal and the human muscle glycogen synthases has a large impact when glycogen is the acceptor substrate. Instead, the catalytic efficiency remains essentially unchanged when small oligosaccharides are used as substrates. Mutants of the human muscle enzyme with reduced affinity for glycogen also show an altered intracellular distribution and a marked decrease in their capacity to drive glycogen accumulation in vivo. The presence of a high affinity glycogen-binding site away from the active center explains not only the long-recognized strong binding of glycogen synthase to glycogen but also the processivity and the intracellular localization of the enzyme. These observations demonstrate that the glycogen-binding site is a critical regulatory element responsible for the in vivo catalytic efficiency of GS.

Biochemical Characterization of the Cell-Biomaterial Interface by Quantitative Proteomics

Surface topography and texture of cell culture substrata can affect the differentiation and growth of adherent cells. The biochemical basis of the transduction of the physical and mechanical signals to cellular responses is not well understood. The lack of a systematic characterization of cell-biomaterial interaction is the major bottleneck. This study demonstrated the use of a novel subcellular fractionation method combined with quantitative MS-based proteomics to enable the robust and high-throughput analysis of proteins at the adherence interface of Madin-Darby canine kidney cells. This method revealed the enrichment of extracellular matrix proteins and membrane and stress fibers proteins at the adherence surface, whereas it shows depletion of extracellular matrix belonging to the cytoplasmic, nucleus, and lateral and apical membranes. The asymmetric distribution of proteins between apical and adherence sides was also profiled. Apart from classical proteins with clear involvement in cell-material interactions, proteins previously not known to be involved in cell attachment were also discovered.

Inducible Nitric Oxide Synthase Deficiency Impairs Matrix Metalloproteinase-9 Activity and Disrupts Leukocyte Migration in Hepatic Ischemia/Reperfusion Injury

Matrix metalloproteinase 9 (MMP-9) is a critical mediator of leukocyte migration in hepatic ischemia/reperfusion (I/R) injury. To test the relevance of inducible nitric oxide synthase (iNOS) expression on the regulation of MMP-9 activity in liver I/R injury, our experiments included both iNOS-deficient mice and mice treated with ONO-1714, a specific iNOS inhibitor. The inability of iNOS-deficient mice to generate iNOS-derived nitric oxide (NO) profoundly inhibited MMP-9 activity and depressed leukocyte migration in livers after I/R injury. While macrophages expressed both iNOS and MMP-9 in damaged wild-type livers, neutrophils expressed MMP-9 and were virtually negative for iNOS; however, exposure of isolated murine neutrophils and macrophages to exogenous NO increased MMP-9 activity in both cell types, suggesting that NO may activate MMP-9 in leukocytes by either autocrine or paracrine mechanisms. Furthermore, macrophage NO production through the induction of iNOS was capable of promoting neutrophil transmigration across fibronectin in a MMP-9-dependent manner. iNOS expression in liver I/R injury was also linked to liver apoptosis, which was reduced in the absence of MMP-9. These results suggest that MMP-9 activity induced by iNOS-derived NO may also lead to detachment of hepatocytes from the extracellular matrix and cell death, in addition to regulating leukocyte migration across extracellular matrix barriers. These data provide evidence for a novel mechanism by which MMP-9 can mediate iNOS-induced liver I/R injury.

Anti-cataractogenic effect of curcumin and aminoguanidine against selenium-induced oxidative stress in the eye lens of Wistar rat pups: An in vitro study using isolated lens

The aim of this study was to investigate whether curcumin and aminoguanidine (AG) prevent selenium-induced cataractogenesis in vitro. On postpartum day 8, transparent isolated lens were incubated in 24 well plates containing Dulbecco's Modified Eagle Medium (DMEM). Isolated lens of group I were incubated with DMEM medium alone. Group II: lenses incubated in DMEM containing 100 μM sodium selenite; group III: lenses incubated in DMEM containing 100 μM sodium selenite and 100 μM curcumin; group IV: lenses incubated in DMEM containing 100 μM sodium selenite and 200 μM curcumin; group V: lenses incubated in DMEM containing 100 μM sodium selenite and 100 μM AG; group V: lenses incubated in DMEM containing 100 μM sodium selenite and 200 μM AG. On day 12, cataract development was graded using an inverted microscope and the lenses were analyzed for enzymic as well as non-enzymic antioxidants, lipid peroxidation (LPO), nitric oxide (NO), superoxide anion (O 2 −) and hydroxyl radical generation (OH ) and inducible nitric oxide synthase (iNOS) activity by Western blotting and RT-PCR. All control lenses in group I were clear (0). In groups II and III, all isolated lenses developed cataract with variation in levels (+++ or ++), whereas isolated lenses from groups IV, V and VI were clear (0). In agreement to this, a decrease in antioxidants and increased free radical generation and also iNOS expression were observed in selenium exposed lenses when compared to other groups. AG (100 μM) was found to be more effective in anti-cataractogenic effect than curcumin (200 μM). Curcumin and AG suppressed selenium-induced oxidative stress and cataract formation in isolated lens from Wistar rat pups, possibly by inhibiting depletion of enzymic as well as non-enzymic antioxidants, and preventing uncontrolled generation of free radicals and also by inhibiting iNOS expression. Our results implicate a major role for curcumin and AG in preventing cataractogenesis in selenite-exposed lenses, wherein AG was found to be more potent.

Identification of Mouse Prp19p as a Lipid Droplet-associated Protein and Its Possible Involvement in the Biogenesis of Lipid Droplets

Prp19p is an integral component of the heteromeric protein complex (the NineTeen complex) in the nucleus, and it is essential for the structural integrity of NineTeen complex and its subsequent activation of the spliceosome. We identified Prp19p, which has never been reported in relation to any function outside of the nucleus, as a member of proteins associated with lipid droplets. Down-regulation of Prp19p expression with RNA interference in 3T3-L1 cells repressed lipid droplet formation with the reduction in the level of expression of perilipin and S3-12. The levels of expression of SCD1 (stearoyl-CoA desaturase-1), DGAT-1 (acyl-CoA diacylglycerol acyltransferase-1), and glycerol-3-phosphate acyltransferase were also reduced in Prp19p down-regulated cells, and a significant decrease in triglycerides was observed. Unlike perilipin, which is one of the most extensively studied lipid droplet-associated proteins, Prp19p is not essential for cAMP- and hormone-sensitive lipase-dependent lipolysis pathways, even though Prp19p is a component of the lipid droplet phospholipid monolayer, and down-regulation of Prp19p represses fat accretion significantly. These results suggest that Prp19p or Prp19-interacting proteins during lipid droplet biogenesis in adipocytes may be considered as another class of potential targets for attacking obesity and obesity-related problems.

Chemical and hormonal determinants of vascular calcification in vitro

Vascular calcification is a complex process that is dependent not only on the physicochemical effects of Ca, PO(4), and pH, but also on smooth muscle factors that may be regulated by these ions as well as by 1,25-dihydroxyvitamin D(3) (calcitriol) and parathyroid hormone (PTH). These minerals and hormones were tested in a model of medial calcification in rat aorta maintained in culture for 9 days. Calcification was quantitated as incorporation of (45)Ca, alkaline phosphatase activity was measured in aortic homogenates, and osteopontin production was measured from immunoblots of culture medium. At 1.8 mM Ca (1.46 mM free), calcification occurred at or above 2.8 mM PO(4). At 3.8 mM PO(4), calcification occurred at or above 1.10 mM free [Ca]. At a constant [Ca] x [PO(4)], calcification varied directly with [Ca] and inversely with [PO(4)]. Calcification was directly related to pH between 7.19 and 7.50 but not altered by PTH or calcitriol. Alkaline phosphatase activity and osteopontin production were increased by Ca, PO(4), calcitriol, and PTH. We conclude that calcification of rat aorta in vitro requires elevation of both [Ca] and [PO(4)], and that [Ca] rather than [PO(4)] or the product of the two is the dominant determinant. The induction of alkaline phosphatase and osteopontin indicates that Ca and PO(4) have effects in addition to simple physicochemical actions. Although PTH and calcitriol did not increase calcification in vivo, they have effects on smooth muscle that could influence calcification in vivo. Calcification is enhanced by alkalinity within the range produced during hemodialysis.