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Guldborg Armstrong posted an update 3 months, 3 weeks ago
Meldonium is a metabolic drug used for treatment of coronary heart disease. The effect of the drug lies in its ability to inhibit synthesis and transport of L-carnitine. At the same time, a long-term deficiency of L-carnitine can theoretically negatively affect the activity of the transcription factor Nrf2, which is extremely important for maintaining mitochondrial balance in cells. We have shown that meldonium therapy for 3 months at a dose of 100 mg/kg in mice causes a decrease in the expression of the Nrf2 gene in the brain. A decrease in the Nrf2 level causes suppression of mitochondrial biogenesis, which is manifested in a decrease in the level of mtDNA and the level of Cox1 expression. However, no negative effect of meldonium on the bioenergetics parameters of mitochondria was found, as evidenced by the maintenance of a stable mitochondrial potential and the level of production of reactive oxygen species. Jne mohth after the end of the meldonium therapy, expression of the genes responsible for mitochondrial biogenesis and mitophagy (p62, Pink1, Tfam) was observed and the expression level of genes responsible for mitochondrial fusion returned to control values. These changes may be associated with the normalization of the level of L-carnitine in brain cells.The homodimeric glycoprotein, anti-mullerian hormone (AMH), described over 70 years ago by A. Jost, is the least studied member of the transforming growth factor beta superfamily. Despite the antitumor activity of AMH discovered at the end of the last century, the creation of effective drugs based on AMH is hindered primarily by the lack of information on the mechanism of various AMH forms interaction with a specific type II receptor (MISRII). read more Previously, we have shown that not only the full-length activated hormone but also its C-terminal fragment (C-rAMH) could bind to MISRII. In this work, using the surface plasmon resonance technique, we compared the interaction of three forms of recombinant AMH (rAMH) with the MISRII analogue – the chimeric protein MISRII-Fc containing AMH type II receptor and a Fc-fragment of the human IgG1 heavy chain. Comparison of the binding of MISRII-Fc, immobilized on a chip with group specificity for human immunoglobulins, to C-rAMH, to intact rAMH (pro-rAMH), and to rAMH containing one uncleaved monomer (hc-rAMH), showed that the KD of the complexes increased 1.7 nM, 88 nM and 110 nM, respectively. Thus, we have shown that C-terminal fragment of AMH has the maximum affinity for the recombinant MISRII analogue, which indicates the prospects for the development of drugs based on this hormone derivative.Mitochondrial dysfunction and ubiquitin-proteasome system (UPS) failure contribute significantly to the development of Parkinson’s disease (PD). The proteasome subunit Rpn13 located on the regulatory (19S) subparticle play an important role in the delivery of proteins, subjected to degradation, to the proteolytic (20S) part of proteasome. We have previously found several brain mitochondrial proteins specifically bound to Rpn13 (Buneeva et al. (2020) Biochemistry (Moscow), Supplement Series B Biomedical Chemistry, 14, 297-305). In this study we have investigated the effect of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and the neuroprotector isatin on the mitochondrial subproteome of Rpn13-binding proteins of the mouse brain. Administration of MPTP (30 mg/kg) to animals caused movement disorders typical of PD, while pretreatment with isatin (100 mg/kg, 30 min before MPTP) reduced their severity. At the same time, the injection of MPTP, isatin, or their combination (isatin + MPTP) had a significant impact on the total number and the composition of Rpn13-binding proteins. The injection of MPTP decreased the total number of Rpn13-binding proteins in comparison with control, and the injection of isatin prior to MPTP or without MPTP caused an essential increase in the number of Rpn13-binding proteins, mainly of the functional group of proteins participating in the protein metabolism regulation, gene expression, and differentiation. Selected biosensor validation confirmed the interaction of Rpn13 subunit of proteasome with some proteins (glyceraldehyde-3-phosphate dehydrogenase, pyruvate kinase, histones H2A and H2B) revealed while proteomic profiling. The results obtained testify that under the conditions of experimental MPTP-induced parkinsonism the neuroprotective effect of isatin may be aimed at the interaction of mitochondria with the components of UPS.Currently, opportunistic fungi of the genus Candida are the main causative agents of mycoses, which are especially severe upon condition of acquired immunodeficiency. The main target for the development of new antimycotics is the cytochrome P450 51 (CYP51) of the pathogenic fungus. Due to the widespread distribution of Candida strains resistancy to inhibitors of the azole class, the screening for CYP51 inhibitors both among non-azole compounds and among clinically used drugs repurposing as antimycotics is becoming urgent. To identify potential inhibitors from the non-azole group, an integrated approach was applied, including bioinformatics analysis, computer molecular modeling, and a surface plasmon resonance (SPR) technology. Using in silico modeling, the binding sites for acetylsalicylic acid, ibuprofen, chlorpromazine and haloperidol (this compounds, according to the literature, showed antimycotic activity) were predicted in the active site of CYP51 of Candida albicans and Candida glabrata. The Kd values of molecular complexes of acetylsalicylic acid, ibuprofen and haloperidol with CYP51, determined by SPR analysis, ranged from 18 μM to 126 μM. It was also shown that structural derivatives of haloperidol, containing various substituents, could be positioned in the active site of CYP51 of Candida albicans with the possible formation of coordination bonds between the hydroxyl groups of the derivatives and the iron atom in the heme of CYP51. Thus, the potential basic structures of non-azole compounds have been proposed, which can be used for the design of new CYP51 inhibitors of Candida fungi.