Delivery of secreted placental alkaline phosphatase (SEAP) gene in vitro and in vivo as a component of recombinant avian adenovirus (CELO)

Recombinant adenoviruses capable of expressing the gene of secreted placentary alkaline phosphatase (SEAP) under control of CMV-promoter was obtained on the basis of CELO avian adenovirus and human adenovirus-5 (Ad5) genomes. The efficiency of the CELO vector was determined in experiments with transduction of human (293, A549, and H1299), mouse (B16), and avian (LMH) cell cultures. It was shown in C57BL/6 mice in vivo that SEAP gene is expressed under conditions of intravenous, intranasal, and intratumoral application of recombinant adenovirus CELO-SEAP. The duration of expression of the alkaline phosphatase CELO = SEAP gene in immunocompetent mouse body was 21 days. The level of SEAP gene expression was measured in the allantois fluid of chicken embryo infected with recombinant adenovirus CELO-SEAP.     

Long non‐coding RNAs in melanoma

Melanoma is the most lethal cutaneous cancer with a highly aggressive and metastatic phenotype. While recent genetic and epigenetic studies have shed new insights into the mechanism of melanoma development, the involvement of regulatory non‐coding RNAs remain unclear. Long non‐coding RNAs (lncRNAs) are a group of endogenous non‐protein‐coding RNAs with the capacity to regulate gene expression at multiple levels. Recent evidences have shown that lncRNAs can regulate many cellular processes, such as cell proliferation, differentiation, migration and invasion. In the melanoma, deregulation of a number of lncRNAs, such as HOTAIR, MALAT1, BANCR, ANRIL, SPRY‐IT1 and SAMMSON, have been reported. Our review summarizes the functional role of lncRNAs in melanoma and their potential clinical application for diagnosis, prognostication and treatment.     

Protective effect of bixin on carbon tetrachloride-induced hepatotoxicity in rats

Background

The liver is an important organ for its ability to transform xenobiotics, making the liver tissue a prime target for toxic substances. The carotenoid bixin present in annatto is an antioxidant that can protect cells and tissues against the deleterious effects of free radicals. In this study, we evaluated the protective effect of bixin on liver damage induced by carbon tetrachloride (CCl₄) in rats.

Results

The animals were divided into four groups with six rats in each group. CCl₄ (0.125 mL kg^-1 body wt.) was injected intraperitoneally, and bixin (5.0 mg kg^-1 body wt.) was given by gavage 7 days before the CCl₄ injection. Bixin prevented the liver damage caused by CCl₄, as noted by the significant decrease in serum aminotransferases release. Bixin protected the liver against the oxidizing effects of CCl₄ by preventing a decrease in glutathione reductase activity and the levels of reduced glutathione and NADPH. The peroxidation of membrane lipids and histopathological damage of the liver was significantly prevented by bixin treatment.

Conclusion

Therefore, we can conclude that the protective effect of bixin against hepatotoxicity induced by CCl₄ is related to the antioxidant activity of the compound.     

Cultivation of reaggregated brain cells in rapidly rotating mini-rollers

An original method of cultivation of reaggregated brain cells with the aid of high-speed portable mini-rollers is described. The mini-roller consists of parallel rollers and an electric motor rotating the flasks at a speed of 60 to 70 rpm. The Moscona technique was used for preparing brain cell suspensions. During cultivation of the suspension of dissociated cells in high-speed mini-rollers, reaggregates with an internal organotypic structure were obtained. The method suggested provides stable and reproducible results.     

Scalable and flexible inference framework for stochastic dynamic single-cell models

Understanding the inherited nature of how biological processes dynamically change over time and exhibit intra- and inter-individual variability, due to the different responses to environmental stimuli and when interacting with other processes, has been a major focus of systems biology. The rise of single-cell fluorescent microscopy has enabled the study of those phenomena. The analysis of single-cell data with mechanistic models offers an invaluable tool to describe dynamic cellular processes and to rationalise cell-to-cell variability within the population. However, extracting mechanistic information from single-cell data has proven difficult. This requires statistical methods to infer unknown model parameters from dynamic, multi-individual data accounting for heterogeneity caused by both intrinsic (e.g. variations in chemical reactions) and extrinsic (e.g. variability in protein concentrations) noise. Although several inference methods exist, the availability of efficient, general and accessible methods that facilitate modelling of single-cell data, remains lacking. Here we present a scalable and flexible framework for Bayesian inference in state-space mixed-effects single-cell models with stochastic dynamic. Our approach infers model parameters when intrinsic noise is modelled by either exact or approximate stochastic simulators, and when extrinsic noise is modelled by either time-varying, or time-constant parameters that vary between cells. We demonstrate the relevance of our approach by studying how cell-to-cell variation in carbon source utilisation affects heterogeneity in the budding yeast Saccharomyces cerevisiae SNF1 nutrient sensing pathway. We identify hexokinase activity as a source of extrinsic noise and deduce that sugar availability dictates cell-to-cell variability.     

Glio-neuronal aggregates in collagen gel: a model for studying the factors affecting development of central nervous system cells

Glio-neuronal aggregates of dissociated cells obtained from embryonic brain during cultivation in rotating flasks were transfered for further cultivation into collagen gel, containing balanced salt solution, serum-free amino acid medium, or complete nutrient medium. Active neurite growth and glial cell migration were observed during cultivation in collagen gel. The experiments have shown that glio-neuronal aggregates may serve as an experimental model for testing the activity of different neuronotrophic and neurite growth stimulating factors.     

Coexpression of all constituents of the cholesterol hydroxylase/lyase system in Escherichia coli cells

Using the pTrc99A/P450scc vector, a plasmid was constructed in which cDNAs for cytochrome P450scc, adrenodoxin reductase, and adrenodoxin are situated in a single expression cassette. This plasmid was shown to direct the synthesis of all the above proteins in Escherichia coli. Their localization in the E. coli cells and stoichiometry were determined. Cell homogenates exhibited cholesterol hydroxylase/lyase activity, due to catalytically active forms of all three proteins. Thus, the full set of constituents of the mammalian cholesterol hydroxylase/lyase system was shown to be synthesized in bacterial cells for the first time.