Vol 512, No 1 (2023)

It was previously established that the original dipeptide mimetic of the 4th loop of NT-3, hexamethylenediamide bis-(N-monosuccinyl-L-asparaginyl-L-asparagine) (GTS-301), has a pronounced neuroprotective effect in vitro at concentrations of 10^–5–10^–12 М. In the present study, experiments on the streptozotocin-induced diabetes model in C57Bl/6 mice showed that GTS-301, administered intraperitoneally for 32 days at doses of  0.1 and 0.5 mg/kg, has antidiabetic activity manifested in the reduction of hyperglycemia, polydipsia, and in the increase of animal survival. The results obtained confirm the concept of the similarity of neurochemical mechanisms underlying the regulation of neurons and β-cells functions.

The mechanoelectrical feedback in the heart is based on the work of mechanically gated (MGCs) and mechanosensitive (MSCs) channels. Since microgravity alters the heart’s morphological and physiological properties, we hypothesized that the expression of both MGCs and MSCs would be affected. We employed RNA transcriptome sequencing to investigate changes in the gene transcript levels of MGCs and MSCs in isolated rat ventricular cardiomyocytes under control conditions and in a simulated microgravity environment. For the first time, our findings demonstrated that simulated microgravity induces alterations in the gene transcript levels of specific MGCs, such as TRPM7, TRPV2, TRPP1, TRPP2, Piezo1, TMEM63A, TMEM36B, and known MSCs, including K_2P2.1, K_2P3.1, Kir6.1, Kir6.2, Na_V1.5, Ca_V1.2, K_V7.1. However, other voltage-gated channels and channels lacking a voltage sensor remained unaffected. These findings suggest that the altered expression of MGCs and MSCs could lead to changes in the net currents across the membrane, ultimately impacting the heart’s function.

Antibodies to histone modifications and an insulator protein involved in the processes of transcription initiation and elongation are mapped in Drosophila polytene chromosomes. The CHRIZ protein (chromatin insulator) and H3K36me3 histone modification (RNA elongation) are detected only in the localization of housekeeping genes (interbands and gray bands of polytene chromosomes) and never in the regions of development genes (black bands and large puffs arising from them). Antibodies to H3S10P histone modification, which is associated with the initial elongation of the RNA strand during transcription, are found exclusively in small puffs, but not in housekeeping gene localization sites or large ecdysone-induced puffs, where housekeeping genes are localized. Antibodies to H4R3me2 histone modification (a co-repressor of the ecdysone receptor) are detected only in large α-induced puffs.

The generation of hydroxyl radicals from hydrogen peroxide in aqueous solutions containing magnetic nanoparticles (MNPs), hemoglobin (Hb), immunoglobulin G (IgG), and human serum albumin (HSA) has been determined. The dependence of the rate of formation of the oxidized product of o-phenylenediamine (o-PDA) on the concentration of MNPs in solution, as well as on the concentration of proteins, was obtained. The peroxidase-like activity of MNPs was shown to decrease in the presence of HSA and IgG, while the addition of Hb to the reaction mixture was leading to its decrease and increase depending on protein concentration. The obtained effects can be used in the development of systems based on MNPs for theranostics, in particular, for suppression of tumor growth, and in predicting the ability of particles to catalyze the generation of reactive oxygen species (ROS) in vivo.

Circulating miR-181а and miR-25, which reflect regulation of the expression of carcinogenesis-related genes, were assayed in patients with invasive carcinoma of no specific type (ICNT) or benign diseases of the breast (BDBs) and in people without pathologies of the mammary gland (controls). MiR-181а expression level proved to be higher compared to control in patients with fibroadenoma and adenosis with low but not high risk of malignant transformation as well as in patients with luminal HER2-negative type B (Lum B HER2–), HER2-positive type (HER2+) and triple-negative breast cancer (TNBC) than in the controls and luminal-type (Lum A) breast cancer. MiR-25 expression level prevailed in patients with Lum B HER2- compared to control, Lum A and TNBC; in patients with TNBC compared to Lum A. Thus, MiR-181а and miR-25 expression levels may be risk indicators of malignant transformation in some patients with BDBs, whereas in patients with ICNT, these levels reflect pathological processes of different directions within the tumor.

The effect of graphene oxide (GO) nanoparticles of 100–200 nm size coated with linear (LP-GO) and branched (BP-GO) polyethylene glycol at concentrations of 5 and 25 μg/mL on the metabolism of Jurkat tumor cells was studied. It was found that LP-GO nanoparticles at a concentration of 25 μg/mL can enhance basal glycolysis of Jurkat T lymphocyte tumor cell line cells, while LP-GO and BP-GO at the same concentration can reduce the indicators of compensatory glycolysis. Despite this, GO nanoparticles coated with linear and branched PEG at a concentration of 5 μg/mL do not have pronounced effects on oxidative phosphorylation and glycolysis of Jurkat cells and could therefore be safe for activated T cells.

The relationship between postures, sleep stages and eye state was established in two species of deer, the Indian sambar (Rusa unicolor) and sika deer (Cervus nippon), based on video recording. In both species, the state of rest or behavioral sleep was recorded in the sternal position, holding the head above the ground, and in the lateral position, with the head resting on the croup or on the ground. Rest accounted for at least 80% of the time in these positions. Based on behavior criteria a substantial portion of rest represented slow-wave sleep. Episodes of rapid eye movements (REM sleep) were recorded in the lateral position. They did not exceed 2 min. When the deer were in the sternal posture, they kept their eyes open most of the time: on average 96% of the time in sambars and 82% in sika deer. Episodes of the open eye in this posture lasted up to 8.4 min in sambars and up to 3.3 min in sika deer. In the lateral position, such episodes were 4 and 1.5 times shorter. Sleeping with open eyes in ungulates may be an important mechanism of maintaining vigilance.

The erythron state was studied in the flounder-gloss (Platichthys flesus, Linnaeus, 1758) during the annual cycle. The number of erythrocytes in the blood and the content of immature erythroid forms were determined: basophilic and polychromatophilic normoblasts in the head kidney (pronephros) and bloodstream. The proliferative activity of cells was judged by the inclusion of ³H-thymidine in immature erythrocytes of circulating blood. It has been showed that the processes of erythropoiesis in the hematopoietic tissue of the flounder-gloss proceed irregularly. The active production of erythroid mass is mainly confined to the post-spawning period. This is evidenced by an increase in the content of immature erythroid forms in the tissue of the pronephros and circulating blood, as well as an increase in their proliferative activity. It is assumed that this is due to the peculiarities of the organization of the red blood system in teleostean fish, which excludes the regular production of erythropoietin in the kidneys.

The paper studies the vertical distribution of Cs-137 trees in the bark of two model trees of Scots pine (Pinus sylvestris L.), selected in the zone of radioactive contamination of the Bryansk region. Each tree was divided into 10 centimeter bars from a length of up to 17 meters, after which the bark along with the bast was separated from each bar into a separate sample. In addition to Cs-137, the content of natural radionuclide K-40 was measured in the bark of model tree No.2 from a comline to 6.5 meters. Measurement of specific activity of technogenic radionuclide Cs-137 and natural radionuclide K-40 by gamma-spectrometric method. For the first time, it was found that in the bark of the studied trees, the vertical distribution of Cs-137 has a wave-like character and can be represented as harmonic oscillations with a period of 1 m. The distribution of potassium also has an oscillatory character similar to caesium, which is consistent with a similar mechanism of behavior of potassium and caesium in woody plants. The correlation coefficient between the values of specific activity of Cs-137 in model trees No.1 and No.2 was 0.80, and between Cs-137 and K-40 in model tree No. 2 was 0.45. Thus, Cs-137 can be used as a radiotracer to assess the intake and distribution of chemical elements in the tissues of scots pine. The found oscillatory nature of the vertical distribution of caesium and potassium in the pine bark has no analogues in the world literature.