The study demonstrates the possibility of using starch to model macromolecular crowding and intracellular medium. A kinetic approach is used to reveal specific functioning of butyrylcholinesterases from different sources in the starch medium. In the study solutions, the Michaelis constant increases, indicating a decrease in the enzyme affinity for the substrate in the presence of the polymer. In the 9% starch solution, this parameter for butyrylcholinesterase from equine serum is 4.6 times higher than in the buffer solution, while the decrease in Vmax is not significant; Vmax values in most solutions are close to those in buffer solution. Model compounds-glycerol and sucrose-are used to impair diffusion control of the reaction studied. Inhibition mechanisms are retained in solutions with starch concentrations, ranging from 1 to 5%, whatever the inhibitor-chlorophos or neostigmine-is used.
In this study, we examined changes in hormonal status, oxidative status, antioxidant defense, and peripheral blood leukocyte telomere length in male Javanese macaques (Macaca fascicularis) following transfer from group housing to individual cages as a model of social isolation. The study was performed in ten male Javanese macaques aged 11-17 years using a longitudinal design: the parameters were assessed in the same animals before transfer to individual cages and after 60 days of isolation. Malondialdehyde (MDA) concentration, superoxide dismutase (SOD) and catalase activities, cortisol, testosterone, and thyroglobulin levels, as well as absolute mean telomere length, were measured. A statistically significant decrease in telomere length (p = 0.0062), MDA concentration, and catalase activity (p < 0.01), as well as an increase in SOD activity and cortisol level (p < 0.05), was observed. Testosterone showed a decreasing trend, whereas thyroglobulin showed an increasing trend. The obtained data indicate systemic changes in the studied parameters in response to isolation. Changes in telomere length and oxidative status may reflect the involvement of mechanisms related to DNA damage and antioxidant system function. The results are consistent with the concept of stages of the general adaptation syndrome.
It is well established that the early stage of mechanical unloading in both humans and animals is characterized by a decline in the activity of the key cellular energy sensor, AMP-activated protein kinase (AMPK). This decline triggers signaling pathways that drive myosin phenotype remodeling and muscle atrophy. However, the molecular mechanisms underlying the reduction in AMPK activity under these conditions remain poorly understood. We hypothesized that elevated activity of protein kinase D1 (PKD1) could contribute to the decline in AMPK activity during the initial stage of rat hindlimb unloading. The present study demonstrates that the suppression of upregulated PKD1 activity via a specific inhibitor (CRT0066101) during 24-hour unloading results in the restoration of AMPK activity in the rat soleus muscle. Thus, we have shown for the first time the contribution of PKD1 to the regulation of AMPK activity in the mammalian postural muscle during the initial stage of hindlimb unloading.
A study was conducted to examine the effects of visible red light phototherapy with a wavelength of 635 nm on the expression of the neuronal protein GAP-43 in the hippocampus of rats. It was shown that the use of PBMT promotes increased GAP-43 synthesis in the hippocampus, with the maximum effect developing by the 6th day of use, which may indicate a cumulative effect of this procedure.
Nuclear export of mRNA is one of the key stages of gene expression in eukaryotes. A wide range of mRNAs is exported by the TREX-2 complex, which includes the PCID2 RNA-binding protein. Previously, we showed that PCID2 is responsible for specific recognition of transcripts, and we identified its binding site on the Drosophila ras2 gene mRNA within the 3'-non-coding region. However, the interaction was not localized for other mRNAs, which makes it impossible to identify the general patterns of PCID2 interaction with mRNA. In this work, we investigated the interaction of PCID2 with the mRNA of the kruppel gene of Drosophila melanogaster. In the EMSA experiments, we showed that PCID2 binds to two fragments of kruppel mRNA, from the 5' non-coding and coding mRNA regions. Thus, the PCID2 binding site can be located not only in the 3'-non-coding region, as in the case of the ras2 mRNA, but also in other mRNA regions. PCID2 has a lower affinity for binding sites in the kruppel mRNA than in the ras2 mRNA. Our analysis of the mRNA structure at three binding sites led to a general interaction model, in which a hairpin-type conformation emerges as the most probable structural motif at these sites.
