Vol 479, No 1 (2018)

We studied the possibility of optimizing modular nanotransporters (MNTs) for the intracellular delivery of antibody fragments into the nuclei of cells of a specified type. Basic MNT with a reduced size retaining the desired functions was obtained, and the principal possibility of obtaining an MNT carrying an antibody fragment by microbiological synthesis was shown.

The dynamics of the expression of genes encoding adhesion molecules, molecules of the connective tissue matrix, and its remodeling enzymes was studied in multipotent mesenchymal stromal cells (MSCs) from human adipose tissue after interaction with cord blood hematopoietic progenitors (HSPCs). An upregulation of ICAM1 and VCAM1, directly proportional to the coculture time (24–72 h), was found. After 72 h of culturing, a downregulation of the genes encoding the majority of matrix molecules (SPP1; COL6A2,7A1; MMP1,3; TIMP1,3; and HAS1) and cell-matrix adhesion molecules (ITGs) was revealed. The detected changes may ensure the realization of the stromal MSC function due to improvement of adhesion and transmigration of HSPCs into the subcellular space.

It was found that cells of different color morphs of the cold-water marine sponges Halichondria panicea (Pallas, 1766) of the class Demospongiae differ in the content of epibionts of bacteria of the genus Pseudoalteromonas. The sponge cells with elevated levels of epibionts of bacteria of the genus Pseudoalteromonas showed an increased expression of Hsp70 proteins but had a reduced level of the proteasomal catalytic beta 5 subunit, which was accompanied by a change in their activity. Probably, epibionts of bacteria of the genus Pseudoalteromonas may affect the ubiquitin–proteasome system in the cells of cold-water marine sponges and, thereby, ensure their adaptive plasticity.

Using an experimental Parkinson’s disease model (symptoms develop in mice after the injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine), we studied the characteristics of the synthesis of dopamine as a possible compensatory mechanism aimed at maintaining the dopamine level in the dopaminergic neurons that survived in this pathology. We found no correlation between the content and activity of tyrosine hydroxylase in the nigrostriatal system. The enzyme activity and the dopamine content showed unidirectional changes in the substantia nigra, but not in the striatum, which is apparently due to triggering other compensatory mechanisms.

The activity of the pool of sgRNA molecules designed for different regions of potato coilin and phytoene desaturase genes was compared in vitro. Due to the presence of nucleotides unpaired with DNA, sgRNA is able not only to inhibit but also to stimulate the activity of the Cas9–sgRNA complex in vitro. Although the first six nucleotides located in the DNA substrate proximally to the PAM site at the 3' end are the binding sites for cas9, they had no significant effect on the activity of the Cas9–sgRNA complex.

A new method for obtaining stable butyrylcholinesterase (BuChE) samples based on the enzyme immobilization in starch and gelatin gels followed by drying is proposed. Coimmobilization of BuChE with the thiol group indicator 5,5'-dithiobis(2-nitrobenzoic) acid did not reduce the activity of BuChE, which allowed us to simplify the procedure and reduce the time of analysis of organophosphorus pesticides. The resulting immobilized samples retained activity for at least 300 days. BuChE samples based on the starch gel showed a greater sensitivity in the determination of pesticides as compared to the samples based on the gelatin gel.

For the first time, the organ-specific expression pattern of the AtUSP (At3g58450) gene, which also undergoes hormonal regulation, was shown. The USP protein encoded by this gene is involved in seed germination of Arabidopsis thaliana and, unlike abscisic acid, stimulates this process.

The combined effect of the zinc magnetic isotope ⁶⁷Zn and weak magnetic field 25–35 mT causes a 2–4-fold increase in the colony-forming ability of bacteria E. coli in comparison with the nonmagnetic isotopes ^{64, 66}Zn. The effects of magnetic field in the range of 2.2–8 mT were detected for all bacteria regardless of the zinc-isotope enrichment of the media. This indicates the sensitivity of intracellular processes to weak magnetic fields. An increase in the ATP concentration in E. coli cells was only detected for the bacteria grown on the medium with the magnetic zinc isotope in the range of 2.2–4.2 mT. The obtained data confirm the existence of stages of intracellular enzymatic processes that are sensitive to magnetic fields and magnetic moments of atomic nuclei.

The patterns of formation of RNA nanoparticles (NPs) during thermal cycling of bacterial total tRNA in the presence of cations Ca²⁺, Mn²⁺, Ni²⁺, Zn²⁺, Co²⁺, and Cu²⁺ were studied. The optimal conditions for the production of NPs were found, and it was revealed that their size depends on the ratio of the concentrations of Me²⁺ and tRNA. The concentration of reagents for obtaining NPs of small size (from 5 to 100 nm) was selected. It was shown that tRNA-based nanoparticles can comprise short (20–50 nt) ribooligonucleotides, including aptamers and siRNAs. The stability of NPs during storage in buffer solutions of various composition was studied. It was found that the initial suspensions of NPs are quite stable, but they are rapidly destroyed in PBS buffer (pH 7.4). A simple and effective stabilizer (polyarginine) was found, the additives of which ensure the preservation of nanoparticles in PBS buffer for more than 5 h. Nanoparticles modified with the stabilizer are resistant to blood serum nucleases and can be used for transfection.

Genes encoding two three-finger toxins TFT-AF and TFT-VN, nucleotide sequences of which were earlier determined by cloning cDNA from venom glands of vipers Azemiops feae and Vipera nikolskii, respectively, were expressed for the first time in E. coli cells. The biological activity of these toxins was studied by electrophysiological techniques, calcium imaging, and radioligand analysis. It was shown for the first time that viper three-finger toxins are antagonists of nicotinic acetylcholine receptors of neuronal and muscle type.