Bulletin of Experimental Biology and Medicine最新文献

We studied the effects of female sex hormones estradiol and progesterone on the expression of CCR5 and CCR8 co-receptor genes (that play an important role in the HIV-1 entry into the cell) in human peripheral blood mononuclear cells (PBMC) isolated from different female donors and infected with HIV-1 subtype G. Female sex hormones produced a dose-dependent effect on the replication of HIV-1 subtype G: low doses of estradiol and high doses of progesterone significantly induced CCR8 expression in PBMC of all donors, which correlated with an increase in viral load by 1.5-1.7 times on average. The exception was one donor, in whom a high dose of estradiol also induced an increase in CCR8 expression. High concentrations of progesterone also enhanced the expression of the CCR5 co-receptor. The detected differences in the co-receptor expression in infected PBMC from different donors indicates that the host genetics may also play an important role in PBMC susceptibility to HIV infection.

The mitotic index is a critical indicator of the proliferative activity of cell populations and is widely used in oncology and stem cell research. One of the most promising methods for its assessment is imaging flow cytometry implemented on the Amnis ImageStream platform using the IDEAS software. A critical evaluation of the built-in Wizards, Cell Cycle-Mitosis algorithm revealed several limitations, including a high degree of operator-dependent variability in gate setting and difficulties in identifying the mitotic population in the absence of distinct peaks on the cell cycle histogram. An alternative approach, the Mean + xSD algorithm, was proposed. This method is based on automated quantitative assessment of the Bright Detail Intensity R3 parameter and excludes the need for manual gating and histogram interpretation. Using the Caco2 and HT-29 cell lines, we demonstrated that the proposed algorithm exhibits accuracy comparable to the classical IDEAS algorithm, and in some cases provides even more reproducible quantification of the mitotic index. These results demonstrate the potential of the new algorithm as a more objective and robust tool for analyzing mitotic activity in cultured cells.

Escherichia phage Ec1-7 was characterized and its efficacy on food products, as well as on stainless-steel surfaces, was evaluated. The bacteriophage with high adsorption rate and short latency period remained stable when exposed to various aggressive factors and demonstrated lytic activity against STEC strains. In addition, the phage did not contain antibiotic resistance, virulence, and toxin genes. In 24 h after application of the bacteriophage, E. coli concentration on lettuce leaves and on stainless-steel surfaces decreased by 98.2 and 90.5%, respectively. In the experiment with artificially contaminated beef, an 81% decrease in bacterial concentration was recorded on day 3 in comparison with the control samples treated with 0.9% NaCl solution. The bacteriophage Ec1-7 exhibited stability and efficacy as a biocontrol agent across diverse test materials.

The study examined implication of miRNA-19b carried by endothelial microparticles (EMPs) in phenotypic switching of vascular smooth muscle cells (VSMCs) and the mechanisms underlying this transformation. The functions of miRNA-19b were assessed by phenotypic switching, proliferation, and migration of VSMCs. The target genes of miR-19b associated with proliferation and migration were revealed by analysis of TargetScan and miRanda databases and verified with luciferase assay. Experiments showed that EMPs could transfer miRNA-19b into VSMCs. Elevated content of miRNA-19b increased expression of contractile phenotypic markers SMA and SM22α and inhibited proliferation and migration of VSMCs. The direct target gene of miRNA-19b turned out to be the mitogen-activated protein kinase 6 (MAPK6). Thus, miRNA-19b in EMPs could inhibit phenotypic transformation of VSMCs from the contractile phenotype to synthetic one and reduce proliferation and migration by down-regulating MAPK6 expression, which can potentially inhibit the development of atherosclerosis.

Coiled-coil domain-containing protein 86 (CCDC86) expression is correlated with the occurrence of lymphoma. However, the expression of CCDC86 in solid tumors such as nasopharyngeal carcinoma (NPC) and the effects of CCDC86 on tumorigenesis remains unclear. Here we studied both problems using tumor tissue samples from NPC patients, NPC cell lines (in vivo), and a model of transplanted tumor in BALB/c nude mice (in vitro). We found that CCDC86 protein was expressed in all studied cell lines, but its expression in CNE1, CNE2, CNE-2Z, 5-8F, and 6-10B cell lines was higher than in nasopharyngeal epithelium cell lines NP69 and NP460. In tumor tissues obtained from patients with NPC, CCDC86 expression was higher than in normal (adjacent) tissues. Knockdown of CCDC86 gene inhibited colony formation and cell proliferation, but increased apoptosis. In BALB/c nude mice transplanted with CCDC86-knockdown CNE-2Z cells, tumors barely grew in comparison with the controls transplanted with CNE-2Z cells transfected with an empty vector lentivirus. In conclusion, CCDC86 is expressed in NPC tissues and NPC cell lines and is closely associated with NPC tumorigenesis. Our study may provide insights into exploring the novel therapeutic targets for NPC.

We studied the participation of the brain dopaminergic system in cognitive processes in rats on the model of spatial learning in the Morris water maze. Administration of the dopamine D1/5-receptor agonist dihydrexidine hydrochloride during repeated training in the Morris water maze resulted in improvement of early memory consolidation by the platform search time index selectively in animals with low abilities to perform the task at this stage of training, but not in individuals with high abilities to early memory consolidation. The agonist was also ineffective in rats with low memory consolidation abilities at all stages of memory formation. In the retrieval phase after repeated training, the agonist improved the retrieval of the skill in rats with low abilities to perform the task. The results illustrate the involvement of the brain dopaminergic system in rats not only in the processes of early spatial memory consolidation, but also in the retrieval of the memory trace after learning.

The autophagy-related structures, the size of the rough endoplasmic reticulum (ER) cisterns, and the expression of apoptosis-related proteins were assessed by transmission electron microscopy and immunohistochemistry in tumor samples from mice with B16 skin melanoma after administration of autophagy inducer (rapamycin) or ER stress inducer (brefeldin A). Brefeldin A stimulated significant ER stress in mouse skin melanoma cells, but rapamycin contributed to the maintenance of cell homeostasis by inducing autophagy, which was confirmed by the presence of autophagy-related structures and significantly smaller sizes of the rough ER cisterns in the group of mice receiving both rapamycin and brefeldin A. Brefeldin A-induced ER stress triggered apoptosis of tumor cells. Moreover, simultaneous stimulation of autophagy and ER stress in tumor cells promoted cytoprotective selective autophagy (reticulophagy) aimed at resolving ER stress, which may be a mechanism underlying the development of chemoresistance in skin melanoma.

We evaluated the response of Mycobacterium tuberculosis to exposure to a new aroylhydrazone derivative using the in vitro mutagenesis followed by genomic analysis of a resistant variant. The compound N'-[(E)-(5-methoxy-1H-indol-3-yl)methylidene]furan-2-carbohydrazide showed minimal inhibitory concentration (MIC) of 0.4412 μM for the reference strain M. tuberculosis H37Rv. An H37Rv clone resistant to elevated (4 × MIC) concentration of this compound recovered on a solid medium was further analyzed by whole genome sequencing and bioinformatics tools. A non-synonymous mutation was detected in the Rv3755c gene at position 302A>G (codon 101H>R, CAC-CGC). The gene-gene interaction analysis showed that this gene belongs to a network that also includes several ABC transporter genes. The identified mutation in Rv3755c may be associated with bacterial adaptation to the selective pressure of the studied aroylhydrazone derivative and reflect a non-specific drug tolerance mechanism. The conserved M. tuberculosis protein Rv3755c, whose function is unknown, may be related to the ABC transporter efflux system.

Tuberculous meningitis (TBM) is the most prevalent and severe manifestation of tuberculosis in CNS. The mechanisms of neurological injury caused by TBM are not well understood. Our study showed that overexpression of WTAP (Wilms tumor 1 associated protein) reduced inflammatory factors and Iba-1 expression induced in BV-2 by H37Rv. It also increased proliferation of neural stem/progenitor cells (NSPCs) and expression of the neuronal marker DCX in these cells. WTAP enhanced expression of high mobility group nucleosome-binding domain-containing protein 3 (HMGN3) by promoting m⁶A methylation of its mRNA. Reducing HMGN3 expression negated WTAP-induced anti-inflammatory and neuroprotective effects in TBM cell model. WTAP inhibited inflammation and microglia activation while promoting NSPC differentiation into neurons via elevation of HMGN3 expression. WTAP/HMGN3 proteins and the corresponding mRNA could be potential targets in the treatment of TBM.

It is known that the senescence-associated secretory phenotype (SASP) can promote senescence of surrounding normal cells. However, SASP signaling during senescence of mesenchymal stromal cells (MSCs) has not yet been fully studied. We determined the pattern of secreted proteins specific to MSCs under stress-induced senescence. Using chromatography-mass spectrometry, proteins specific to the secretome of senescent or "young" cells were identified. The secretome of senescent cells contains proteins both associated with senescence (LOXL2, CCL2, PLAT, SERPINE2, etc.) and important for reducing the impact of these processes, in particular, proteins responsible for inhibition of oxidative stress (MIF, PRDX5, GSTM2), detoxification of methylglyoxal (GLO1), and suppression of inflammatory reactions (GAS6, GSTM2). The obtained results indicate the complex etiology of aging and the ambiguity of the function of SASP within the paracrine induction of aging of neighboring cells.