Application of cell co-culture system to study fat and muscle cells

Animal cell culture is a highly complex process, in which cells are grown under specific conditions. The growth and development of these cells is a highly unnatural process in vitro condition. Cells are removed from animal tissues and artificially cultured in various culture vessels. Vitamins, minerals, and serum growth factors are supplied to maintain cell viability. Obtaining result homogeneity of in vitro and in vivo experiments is rare, because their structure and function are different. Living tissues have highly ordered complex architecture and are three-dimensional (3D) in structure. The interaction between adjacent cell types is quite distinct from the in vitro cell culture, which is usually two-dimensional (2D). Co-culture systems are studied to analyze the interactions between the two different cell types. The muscle and fat co-culture system is useful in addressing several questions related to muscle modeling, muscle degeneration, apoptosis, and muscle regeneration. Co-culture of C2C12 and 3T3-L1 cells could be a useful diagnostic tool to understand the muscle and fat formation in animals. Even though, co-culture systems have certain limitations, they provide a more realistic 3D view and information than the individual cell culture system. It is suggested that co-culture systems are useful in evaluating the intercellular communication and composition of two different cell types.     

Impact of stress hormone on adipogenesis in the 3T3-L1 adipocytes

Stress hormone is known to play a vital role in lipolysis and adipogenesis in fat cells. The present study was carried out to evaluate the effect of epinephrine on adipogenesis in the 3T3-L1 cells. The investigation on adipogenesis was done in both mono and co-cultured 3T3-L1 cells. 3T3-L1 preadipocytes and C2C12 cells were grown independently on transwell plates and transferred to differentiation medium. Following differentiation, C2C12 cells transferred to 3T3-L1 plate and treated with medium containing 10 μg/ml of epinephrine. Adipogenic markers such as fatty acid binding protein 4, peroxisome proliferator activating receptor, CCAAT/enhancer-binding protein, adiponectin, lipoprotein lipase and fatty acid synthase mRNA expressions were evaluated in the 3T3-L1 cells. Epinephrine treatment reduced adipogenesis, evidenced by reducing adipogenic marker mRNA expression in the 3T3-L1 cells. In addition, glycerol accumulation and oil red-O staining supported the reduced rate of adipogenesis. Taking all together, it is concluded that the stress hormone, epinephrine reduces the rate of adipogenesis in the mono and co-cultured 3T3-L1 cells. In addition, the rate of adipogenesis is much reduced in the co-cultured 3T3-L1 cells compared monocultured 3T3-L1 cells.     

Effects of prenatal exposure to diclofenac sodium and saline on the optic nerve of 4- and 20-week-old male rats: a stereological and histological study

We investigated the effects of diclofenac sodium (DS) on development of the optic nerve in utero. Pregnant female rats were separated into three groups: control, saline treated and DS treated. Offspring of these animals were divided into 4-week-old and 20-week-old groups. At the end of the 4th and 20th weeks of postnatal life, the animals were sacrificed, and right optic nerves were excised and sectioned for ultrastructural and stereological analyses. We demonstrated that both DS and saline produced structural and morphometric changes in the total axon number and density of axons, but decreased the myelin sheath thickness in male optic nerves. All ultrastructural and morphometric features were well developed in 20-week-old rats. We showed that development of the optic nerve continues during the early postnatal period and that some compensation for exposure to deleterious agents in utero may occur during early postnatal life.     

Network analysis of temporal functionalities of the gut induced by perturbations in new-born piglets

Background

Evidence is accumulating that perturbation of early life microbial colonization of the gut induces long-lasting adverse health effects in individuals. Understanding the mechanisms behind these effects will facilitate modulation of intestinal health. The objective of this study was to identify biological processes involved in these long lasting effects and the (molecular) factors that regulate them. We used an antibiotic and the same antibiotic in combination with stress on piglets as an early life perturbation. Then we used host gene expression data from the gut (jejunum) tissue and community-scale analysis of gut microbiota from the same location of the gut, at three different time-points to gauge the reaction to the perturbation. We analysed the data by a new combination of existing tools. First, we analysed the data in two dimensions, treatment and time, with quadratic regression analysis. Then we applied network-based data integration approaches to find correlations between host gene expression and the resident microbial species.

Results

The use of a new combination of data analysis tools allowed us to identify significant long-lasting differences in jejunal gene expression patterns resulting from the early life perturbations. In addition, we were able to identify potential key gene regulators (hubs) for these long-lasting effects. Furthermore, data integration also showed that there are a handful of bacterial groups that were associated with temporal changes in gene expression.

Conclusion

The applied systems-biology approach allowed us to take the first steps in unravelling biological processes involved in long lasting effects in the gut due to early life perturbations. The observed data are consistent with the hypothesis that these long lasting effects are due to differences in the programming of the gut immune system as induced by the temporary early life changes in the composition and/or diversity of microbiota in the gut.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1733-8) contains supplementary material, which is available to authorized users.     

Hydroprocessing of sunflower oil-gas oil blends over sulfided Ni-Mo-Al-zeolite beta composites

Mixtures of sunflower oil and a straight run gas oil in the diesel fuel range were hydroprocessed over sulfided NiO(3%)-MoO3(12%)-γ-Al2O3 incorporating 0, 15 or 30 wt.% zeolite beta (BEA). The studies were carried out at 320-350 °C; 30-60 bars, and weight hourly space velocities (WHSV), 1-4 h(-1). Catalyst containing 30% BEA achieved nearly 100 % conversion of the vegetable oil into hydrocarbons at 330 °C, 60 bars and a WHSV of 2 h(-1) compared to 95.5% by the Ni-Mo-γ-alumina catalyst without BEA. Hydroprocessing with blends containing oleic acid revealed that the catalysts were able to transform the acid into hydrocarbons. An analysis of the ratios of the n-C18 and n-C17 paraffins formed from the vegetable oil at different process conditions revealed that the catalyst containing 15% BEA was most active for hydrodeoxygenation. The gas oil-hydrodesulfurization activity of the Ni-Mo-Al2O3 was enhanced by the addition of BEA by more than 10%.     

1,000 structures and more from the MCSG

Background  

The Midwest Center for Structural Genomics (MCSG) is one of the large-scale centres of the Protein Structure Initiative (PSI). During the first two phases of the PSI the MCSG has solved over a thousand protein structures. A criticism of structural genomics is that target selection strategies mean that some structures are solved without having a known function and thus are of little biomedical significance. Structures of unknown function have stimulated the development of methods for function prediction from structure.     

Evolving DNA motifs to predict GeneChip probe performance

Background  

Affymetrix High Density Oligonuclotide Arrays (HDONA) simultaneously measure expression of thousands of genes using millions of probes. We use correlations between measurements for the same gene across 6685 human tissue samples from NCBI's GEO database to indicated the quality of individual HG-U133A probes. Low correlation indicates a poor probe.     

Computational prediction and analysis of impact of the cross‐talks between JNK and P38 kinase cascades

Signal transduction is a complex protein signaling process with a rich network of multifunctional interactions that occur in a non‐linear fashion. Mitogen‐activated protein kinase (MAPK) signal transduction pathways regulate diverse cellular processes ranging from proliferation and differentiation to apoptosis. In mammals, out of five, there are three well characterized subfamilies of MAPKs ‐ ERKs (Extracellular signal‐regulated kinases), JNKs (c‐Jun N‐terminal kinases), and P38 kinases, and their activators, are implicated in human diseases and are targets for drug development. Kinase cascades in MAPK pathways mediate the sensing and processing of stimuli. To understand how cells makes decisions, the dynamic interactions of components of signaling cascades are important rather than just creating static maps. Based on enzyme kinetic reactions, we have developed a mathematical model to analyze the impact of the cross‐talks between JNK and P38 kinase cascades. Cross‐talks between JNK and P38 kinase cascades influence the activities of P38 kinases. Responses of the signals should be studied for network of kinase cascades by considering cross‐talks.     

Protein evolution in different cellular environments: cytochrome b in sharks and mammals

DNA sequences for the mitochondrial cytochrome b gene were determined for 13 species of sharks. Rates and patterns of amino acid replacement are compared for sharks and mammals. Absolute rates of cytochrome b evolution are six times slower in sharks than in mammals. Bivariate plots of the number of nonsynonymous and silent transversions are indistinguishable in the two groups, however, suggesting that the differences in amino acid replacement rates are due primarily to differences in DNA substitution rates. Patterns of amino acid replacement are also similar in the two groups. Conserved and variable regions occur in the same parts of the cytochrome b gene, and there is little evidence that the types of amino acid changes are significantly different between the groups. Similarity in the relative rates and patterns of protein change between the two groups prevails despite dramatic differences in the cellular environments of sharks and mammals. Poor penetrance of physiological differences through to rates of protein evolution provides support for the neutral theory and suggests that, for cytochrome b, patterns of evolution have been relatively constant throughout much of vertebrate history.