Autophagy in Human Retinal Neurons in Glaucoma.

Immunohistochemical and ultrastructural analysis revealed signs of structural alterations in neurons and autophagy in all layers of the human retina at the end-stage glaucoma. The most pronounced destructive changes associated with swelling and destruction of mitochondria, endoplasmic reticulum, and Golgi apparatus, as well as structural signs of impaired synaptic activity and apoptosis were noted in ganglion, bipolar, and amacrine neurons. In the structure of photoreceptor cells, alone with destructive processes associated with structural alterations of rods and cones in the outer membrane discs, as well as swelling of organelles, we observed processes aimed at the maintenance of cell homeostasis. Structural signs of autophagy (mainly mitophagy) and changes of the ultrastructural organization in rod neurons were more pronounced than in cones.

Ultrastructural Organization of Uveal Melanoma Stromal Cells.

Typical blood capillaries and vessels in uveal melanoma were shown and different types of uveal melanoma stromal cells were determined by electron microscopy and immunohistochemical analysis. Macrophages, fibroblasts of varying degrees of differentiation and endothelial-like cells with numerous caveolae in the cytoplasm were found in the channels of the extracellular matrix surrounding accumulations of tumor cells. The presence local structures positively stained for markers of the blood and lymphatic vessels (CD31 and podoplanin) in channels of the extracellular matrix suggests that the described endothelial-like cells can be the structural basis for blood and lymphatic vessels of the tumor.

[Cytokine gene polymorphisms in patients with age-related macular degeneration].

AIM: To establish possible association between age-related macular degeneration (AMD) and cytokine genotype polymorphisms; for that promoter regions of a number of cytokine genes were studied, namely, TNF-A863C, TNF-A308G, TNF-A238G, IL1ß-C-31T, IL4-C590T, IL6-C174G, and IL10A-1082G. MATERIAL AND METHODS: A total of 102 AMD and 100 non-AMD participants in the same age range were examined at the Novosibirsk branch of the Academician S.N. Fyodorov IRTC «Eye Microsurgery¼. In all cases restriction fragment length polymorphism analysis was performed. RESULTS: The frequency of TNF-308 GA and IL10-1082 GG genotypes was higher in AMD patients than in the controls, while the TNF-308 АA minor genotype has proved protective against the disease. Moreover, AMD has been found to be positively related to 48 genotypic combinations and negatively - to 32 (with specificity as high as 98-99%). The odds ratio was also higher in combination analysis as compared to monogenotypes. CONCLUSION: Complex genetic analysis of cytokines gives an idea of the balance of proinflammatory and anti-inflammatory cytokines in AMD and, therefore, plays an important role in studying the disease pathogenesis and exploring therapeutic options.

[Characteristics of exosomes andmicroparticles discovered in human tears].

Exosomes represent a sort of extracellular vesicles, which transfer molecular signals in organism and possess markers of producing cells. Our study was aimed at search of exosomes in the tears of healthy humans, confirmation of their nature and examination of exosome morphological and molecular-biological characteristics. The tears (110-340 ml) were collected from 24 healthy donors (aged 46-60 years); individual probes were centrifuged at 20000 g for 15 min to pellet cell debris. The supernatants were examined in electron microscope using negative staining; and they were also used for isolation and purification of the exosomes by filtration (100 nm pore-size) and double ultracentrifugation (90 min at 100000 g, 4°C). The "pellets" were subjected to electron microscopy, immunolabeling. The RNA and DNA were isolated from the samples, and their sizes were evaluated by capillary electrophoresis, the concentration and localization of nucleic acids were determined. Sequencing of DNA was performed using MiSeq ("Illumina", USA), data were analyzed using CLC GW 7.5 ("Qiagen", USA). Sequences were mapped on human genome (hg19). Electron microscopy revealed in supernatants of the tears cell debris, spherical microparticles (20-40 nm), membrane vesicles and macromolecular aggregates. The "pellets" obtained after ultracentrifugation, contained microparticles (17%), spherical and cup-shaped EVs (40-100 nm, 83%), which were positive for CD63, CD9 and CD24 receptors (specific markers of exosomes). Our study showed presence of high amount of exosomes in human tears, and relation of the exosomes with RNA (size less than 200 nt) and DNA (size was 3-9 kb). Sequencing of the DNA showed that about 92% of the reads mapped to human genome.

[Part of the matrix on the 5' side from codon in the E-segment is close to protein S26 on the human 80S ribosome]. / Chast' matritsy s 5'-storony ot kodona v E-uchastke sblizhena s belkom S26 na 80S ribosome cheloveka.

Positioning of mRNA on the 80S ribosome upstream the E site bound codon was studied using derivatives of nona- and dodecaribonucleotides containing the triplet UUU coding for Phe at the 3'-terminus, and a perfluorophenylazide cross-linker on either the first or the third nucleotide. Two sets of the mRNA analogues were used, with the photoactivatable groups on either the C5 atom of the uridine or the N7 atom of the guanosine. The modified nucleotides were directed to positions from -4 to -9 with respect to the first nucleotide of the P site bound codon by tRNA(Phe) cognate to the triplet UUU targeted to the P site. Mild UV-irradiation of ribosomecomplexes with tRNA(Phe) and mRNA analogues resulted in the cross-linking to the 40S subunits preferentially, mainly to the proteins. The principal target for the cross-linking was protein S26 in all cases. Location of the photoactivatable group on the nucleotide at position -4 lead also to the minor cross-linking to protein S3, and at position -6 to protein S14. In the absence of tRNA, all mRNA analogues cross-linked to protein S3.