[Effects of diet on the gut microbiome in patients with depression]. / Vliyanie diety na mikrobiom kishechnika u patsientov s depressiei.

OBJECTIVE: To investigate the effects of diet on the gut microbiota and to assess the relationship of these factors with depression. MATERIAL AND METHODS: Microorganisms that predominate in depressed patients were identified and associations of the identified organisms with the patients' diet were performed. Fourteen depressed patients and 14 healthy volunteers with the same socio-demographic parameters were included in the study. The Hamilton Depression Scale, Generalized Anxiety Disorder Questionnaire, and the Center for Epidemiologic Studies Questionnaire were used. RESULTS: Erysipelatoclostridium and Clostridium innocuum species were 11.3 and 14.4 times higher in depressed patients compared with healthy controls. Fusicatenibacter saccharivorans, Faecalibacterium prausnitzii and Roseburia faecis species, as well as members of the genus Roseburia were statistically significantly more abundant in the healthy volunteers group (6.5, 2.14, 8.75 and 5.2 times more frequently compared to patients). The presence of these microorganisms was correlated with dietary components. CONCLUSION: Our study revealed groups of microorganisms that differ in healthy volunteers and depressed patients. The association of these microorganisms with the diet was shown, which partially confirmed the influence of a «healthy diet¼ on the development of depressive disorders.

Social and Cognitive Impairments in Rat Offspring after Ultrasound-Induced Prenatal Stress.

We studied the possibility of developing an autism model based on chronic prenatal psychological stress caused by variable frequency ultrasound 20-45 kHz. The offspring of female rats stressed during pregnancy demonstrated reduced time of social contacts in the social interaction test, increased anxiety in the open-field test, and memory impairment in the Morris water maze test in comparison with the control (intact) rat offspring. We also found a reducing trend in the BDNF gene expression in the amygdala in males of the experimental group. The results showed the possibility of developing the animal autism model based on prenatal stress.

Chronic Exposure to Ultrasonic Frequencies Selectively Increases Aggression in Rats.

We studied aggression in male Sprague-Dawley rats in a model of a depressive-like state induced by unpredictable treatment with ultrasonic waves with the frequencies of 20-45 kHz for 1, 2 or 3 weeks. We did not find any increase in the number of animals exhibiting aggression in the "resident-intruder" test after the treatment of any selected duration. However, the aggressive animals exposed to ultrasound exhibited the substantially increased number of attacks and their total duration as well as decreased latency of the first attack compared to the respective indices in the animals of the control group. Taking this into account, it is possible to suggest that the initial level of aggression increases in a model of ultrasonic chronic stress.

Post-Weaning Social Isolation Disturbs Gene Expression in Rat Brain Structures.

Post-weaning social isolation of male Wistar rats for 10 weeks led to an increase of their aggressiveness, sensorimotor reactivity, and cognitive deficiency, manifesting in training disorders evaluated by the acoustic startle response (amplitude of the response decreasing). Expression of gene encoding serine protease prolyl endopeptidase (EC 3.4.21.26) in the frontal cortex was higher than in control rats kept in groups, while the level of mRNA of the gene encoding dipeptidyl peptidase IV (EC 3.4.14.5) did not differ from the control in any of the brain structures. The levels of serotonin transporter gene mRNA in the striatum and hypothalamus were higher than in the control. No appreciable changes in the expression of genes encoding tryptophan hydroxylase-2 and monoaminoxidase A and B in the frontal cortex, striatum, amygdala, hypothalamus, and hippocampus were detected. The data indicated the involvement of genes associated with the serotoninergic system in the mechanisms of mental disorders induced by post-weaning social isolation and suggest the gene encoding prolyl endopeptidase as a candidate gene involved in the pathogenesis of these disorders.

[Genetic aspects of schizophrenia]. / Geneticheskie aspekty shizofrenii.

Schizophrenia is a disease with a complex non-Mendelian inheritance mechanism in most cases involving the combined action of a large number of genes. Identifying of genomic variations associated with schizophrenia endophenotypes has a great potential. This review describes genetic markers of the disease, current methods of their analysis, including genome-wide association study (GWAS). Certain genes with mutations that increase the risk of schizophrenia are described. Functional polymorphisms with phenotypic expression, which are significantly associated with clinical manifestation of schizophrenia, can serve as useful genetic markers. The authors highlight that currently there are no certain susceptibility genes. Further global research and search for markers in different population groups are needed.

[Blood-brain barrier permeability in healthy rats and rats with experimental C6 glioma after fractionated radiotherapy of the brain].

OBJECTIVE: To evaluate the effect of fractionated radiotherapy on permeability of the blood-brain barrier in healthy rats and rats with C6 glioma in vivo. MATERIAL AND METHODS: An increase in BBB permeability in C6 glioma was assessed by dynamic MRI monitoring (glioma size before and after radiation therapy in combination with immunotherapy, n=30) and confocal microscopy (fluorescence imaging of tumor invasion boundaries in a dose-dependent experiment for the amount of injected antibodies). In healthy rats, BBB permeability to macromolecular substances (MMS) was assessed by ELISA (n=23, 192 plasma samples) and confocal microscopy (n=7). RESULTS: It was shown that BBB permeability to biological macromolecules in blood-brain and brain-blood directions was increased after fractionated radiotherapy. CONCLUSION: Drug delivery to the brain can be improved using therapeutic doses of radiation treatment that affects the BBB and minimizes the risk of serious side effects that are often associated with the drug dose.

Effect of γ-irradiation on expression of tight and adherens junction protein mRNA on in vitro blood-brain barrier model.

We studied the effect of γ-irradiation on HUVEC endothelial cells co-cultured with allogeneic astrocytes. This 2D in vitro model of the blood-brain barrier has the same parameters as cerebral microvascular endothelial cells forming the blood-brain barrier and allows reproducing its functions in vivo. Dose-dependent changes in cell morphology and violation of monolayer integrity were observed. Real-time PCR and immunocytochemical analysis revealed changes in the expression of tight (ZO-1, claudin-5) and adherens junction protein (vascular endothelial cadherin, ß-catenin) mRNA. Expression of tight and adherens junction proteins mRNA decreased in 2, 24, and 48 h after irradiation in doses of 2, 4, and 6 Gy. Significant dose-dependent changes were found only for ß-catenin mRNA expression in 2 h after exposition. This model of blood-brain barrier in vitro can be used for studying the molecular mechanisms regulating permeability of cerebral endothelium under normal conditions and after pathological exposures, e.g. γ-irradiation.

Expression of VEGF, GFAP, and BDNF genes in the brain of rats after fractionated γ-irradiation according to different protocols.

The expression of VEGF, GFAP, and BDNF genes in the nervous tissue changed on weeks 4, 8, and 12 after fractionated irradiation of the brain according to different protocols in a fixed total dose of 36 Gy. The expression of VEGF gene decreased in the prefrontal cortex and hippocampus after 4 and 8 weeks. After week 12, the expression of VEGF normalized in the prefrontal cortex and remained low in the hippocampus. The expression of GFAP gene was maximum in the prefrontal cortex after week 4 and returned to normal in week 12. In the hippocampus, the expression of GFAP was low only after week 12. The expression of BDNF gene was reduced only during the week 8 and this decrease was directly proportional to the single dose. Hence, fractionated γ-irradiation with fixed total dose differently modified gene expression in the nervous tissue.

Treatment of poorly differentiated glioma using a combination of monoclonal antibodies to extracellular connexin-43 fragment, temozolomide, and radiotherapy.

Antitumor efficiencies of monoclonal antibodies to connexin-43 second extracellular loop (MAbE2Cx43), temozolomide, and fractionated γ-irradiation in the monotherapy mode and in several optimized combinations were studied in Wistar rats with induced C6 glioma. The survival of animals with glioma and the dynamics of intracerebral tumor development were evaluated by MRT. Temozolomide monotherapy (200 mg/m(2)) and isolated radiotherapy in a total dose of 36 Gy shifted the survival median from 28 days (no therapy) to 34 and 38 days, respectively; 100% animals died under conditions of temozolomide monotherapy and radiotherapy. Monotherapy with MAbE2Cx43 in a dose of 5 mg/kg led to significant regression of the tumor (according to MRT data), cure of 19.23% animals with glioma, and prolongation of the survival median to 39.5 days after tumor implantation. Combined therapy with MAbE2Cx43 and temozolomide completely abolished the antitumor effect (survival median 29 days). Treatment with MAbE2Cx43 in combination with radiotherapy was associated with mutual boosting of the therapeutic efficiencies, leading to a significant inhibition of tumor development and prolongation of the survival median to 60 days. The mechanism of tumorsuppressive activity of the antibodies could be due to connexon blockade in Cx43-positive glioma cells in the peritumor invasion zone. Higher efficiency of combined therapy was presumably due to the increase in blood-brain barrier permeability for antibodies after irradiation of the brain and to additional inhibitory effect of antibodies towards radioresistant migrating glioma cells. The results suggested that MAbE2Cx43 could be effective as the first-line drug in combined therapy for poorly differentiated gliomas.

Organ, cellular, and subcellular localization of brain-specific anion transporter BSAT1.

Organ, cellular, and subcellular localization of brain-specific anion transporter BSAT1 was studied in rats using antibodies to the extracellular fragment (451-557 a.a). The antibodies were shown to recognize the antigen predominantly localized in the nervous tissue, tumors of glial origin, and primordial ovarian follicles. The absence of BSAT1 immunofluorescence signal in kidney and liver sections and accumulation of (125)I labeled antibodies to BSAT1 in these organs indicate that these antibodies do not cross-react with the most common isoforms of OATP expressed in these organs. Analysis of the cellular localization suggests that in the brain, BSAT1 is localized predominantly in astrocytes, but not in endothelial cells, as was previously reported. Laser scanning confocal microscopy with a set of relevant trackers revealed membrane localization of BSAT1. Taking into account the data on the of localization, we can conclude that antibodies to BSAT1 451-557 can be used for basic research of the transport of thyroxin and prostaglandins across the blood brain barrier and for testing the systems for targeted transport of diagnostic preparations and drugs across the blood brain barrier, e.g. to astroglial tumors.