Correlations of Expression Levels of Lung Cancer Marker Gene Eno2 and Genes of Carcinogenesis and Apoptosis in the Hypothalamus of Mice with Depression-Like Behavior.

We experimentally demonstrated that chronic social stress during the development of a depression-like state enhances lung metastasis and modifies the expression of many carcinogenesis- and apoptosis-related genes in the hypothalamus of mice, including genes involved in lung cancer pathogenesis in humans. Analysis of the expression of genes encoding the major clinical markers of lung cancer in the hypothalamus of mice with depression-like behavior revealed increased expression of the Eno2 gene encoding neuron-specific enolase, a blood marker of lung cancer progression in humans. It was shown that the expression of this gene in the hypothalamus correlated with the expression of many carcinogenesis- and apoptosis-related genes. The discovered phenomenon may have a fundamental significance and requires further studies.

[Changes in Expression of Genes Associated with Calcium Processes in the Hippocampus in Mice Exposed to Chronic Social Stress].

Whole-transcriptome data were used to study the changes in expression of genes coding proteins involved in the calcium regulation processes in the hippocampus of male mice with symptoms of depression caused by chronic social defeat stress. Cacna1g, Cacnb3, Camk1g, Camk2d, Camk2n2, Caly, Caln1, S100a16, and Slc24a4 genes were upregulated in the hippocampus of depressed mice compared to a control, while Cacna2d1, Cacng5, Grin2a, and Calm2 were downregulated. The greatest number of significant correlations was observed between the expression level of Calm2, which showed the highest transcriptional activity, and other differentially expressed genes. Calcium signaling in the hippocampus was assumed to be disrupted in mice exposed to chronic social defeat stress. The involvement of Calm2, Camk1g, Camk2d, and Camk2n2 genes in the process is discussed.

[Serotonergic genes in the development of anxiety/depression-like state and pathology of aggressive behavior in male mice: RNA-seq data].

In course of daily agonistic interactions, mice tend to stratify into those with chronic social defeats and those that repeatedly display aggression, which lead to the development of mixed anxiety/depression-like state and the pathology of aggressive behavior, respectively. Using the data of whole transcriptome analysis (RNA-seq), the changes in the expression of serotonergic genes involved in the synthesis, inactivation, and reception of serotonin, as well as of the Creb1 (transcription factor) gene and the Bdnf (brain-derived neurotrophic factor) gene were detected in the striatum (STR), ventral tegmental area (VTA), midbrain raphe nuclei (MRN), hypothalamus (HYP), and hippocampus (HIP) of defeated and aggressive male mice. In mice of both groups, the Tph2, Ddc, Slc6a4, Htr2a, Htr3a, Htr5b, Slc18a2, and Bdnf genes were downregulated in the MRN and the Tph2, Ddc, and Slc6a4 genes were upregulated in the VTA. These changes were more significant in defeated mice. The Htr5b gene has first been shown to be involved in mechanisms of depression and pathology of aggressive behavior. In the defeated mice, the expression levels of the Htr4 and Aldh1b1 genes were increased in the MRN, and expression levels of the Maob, Htr4, Htr1a, and Slc18a2 genes were increased in the VTA, while the expression level of the Htr3a gene was decreased. In the HYP of aggressive mice the Maoa, Htr2a, Htr2c, and Creb1 genes were downregulated and the Htr6 gene was upregulated. In the defeated mice, the Maoa and Creb1 genes were downregulated and the Htr6 and Aldh1b1 genes were upregulated in the HYP. In the STR, the Htr1a gene was downregulated and the Htr7 and Bdnf genes were upregulated. The Htr1b gene was upregulated in the HIP. The coexpression of dopaminergic and serotonergic genes in the MRN and VTA in the control of pathological behaviors is discussed. Thus, the complex pattern of differential expression of serotonergic genes in brain regions developing under repeated agonistic interactions in mice in dependence on behavioral pathology have been observed.

[Altered Expression of Neurotransmitters Systems' Genes in the Ventral Tegmental Area of Depressive Male Mice: Data of RNA-Seq].

Chronic social defeat stress (CSDS) leads to the development of mixed anxiety/depression-like state in male mice similar to those in humans. It has been shown that, under CSDS, the adult brain undergoes changes in the functioning neurotransmitter systems in different brain regions. In this experiment we are focused on the analysis of expression of genes encoding proteins related with the metabolism and receptors of serotonin, catecholamines, GABA and glutamate in the ventral teg- mental area which is important for regulation of motivations, emotions and is involved into mech- anisms of affective disorders. Mixed anxiety/depression-like state was generated in male mice by exposure to CSDS during 20 days. The collected samples of the ventral tegmental area were se-- quenced at JSC Genoanalytica,(http://genoanalytica.ru/, Moscow, Russia).'We found that genes, related with serotonin (Tph2, Maob, SIc6a4, Htr4, Htr1a) were upregulated but expression of Htr3a gene was downregulated in the ventral tegmental area of depressive mice in comparison with the control. Besides, upregulation of dopaminergic Th, Ddc, Slc6a3, Sic18a2, Drd2, and Maob genes was found while noradrenergic Dbh, Slc6a2, Adra2c, and Adra2a genes were downregulated. Ex- pression of GABAergic Gabral, Gabra2, Gabrg2, Gabrg], Gabrq, Gad], and Gad genes as well as glutamatergic Grial, Gria2, Grik2, Grm2, Grm5, and Slc 7a8 genes were increased under CSDS. Development of mixed anxiety/depression-like state under CSDS in male mice is accompanied by increased expression of genes coding the proteins participating in the metabolism and receptions of serotonergic, dopaminergic, glutamatergic and GABAergic systems. Expression of genes coding the adrenergic reception is decreased. It is supposed that Drd2 H Htr3a genes may play the key role in the synchronization of other genes of neurotransmitter systems.

[Relationship of Anxiety and Depression in the Development of Mixed Anxiety/Depression Disorder. An Experimental Study of Comorbidity Mechanisms (Review)].

As clinical practice and experimental studies show, symptoms of depression and anxiety often accompany each other. It is well known that combination of anxiety and depression in patients is treated more slowly, requires large doses of drugs, increases the likelihood of suicide and often leads to relapse. Furthermore, antidepressants and anxiolytics exert its therapeutic effect in limited cases even in monopolar anxiety or depression state. In this review of literature and our own data the relationship of anxiety and depression is analyzed. It has been shown with using the model of mixed anxiety/depression disorder caused by chronic social defeat stress, that the anxiety and depression are changed under the influence of psychotropic drugs independently.

[Comparative Analysis of Behavior in The Open-field Test in Wild Grey Rats (Rattus norvegicus) and in Grey Rats Subjected to Prolonged Selection for Tame And Aggressive Behavior].

The aim of this work is analysis of the open-field behavior in grey rats selected for the tame and aggressive behavior in comparison with the wild grey rats. Significant influences of the rat group factor on the 13 of 19 behavioral features studied in the open-field were found. This effect, in general, depends on existence of great differences between behaviors of the wild rats from the one hand and behaviors of the tame and aggressive rats from the other. The behaviors of the rats from the last two groups are practically identical. Multidimensional analysis confirms the distinct separation in coordinates of the two main components of the wild rat behavior from the behavior of both the tame and selectively bred aggressive rats. The first main component dimension corresponds to the grade of fear, which was significantly enhanced in the wild rats. So, in spite of the equality of behavioral aggressiveness of the wild rats and the rats selected for aggression with the glove test, the behavior of selected aggressive rats in the open-field is analogous to behavior of the rats selected for tameness. Comparison of behavioral features with the hormonal stress responsiveness allowed us to conclude that the aggressive behavior of the wild and se lected for aggression rats based on different motivational and neuroendocrine processes.

[Changes in the Expression of Dopaminergic Genes in Brain Structures of Male Mice Exposed to Chronic Social Defeat Stress: An RNA-seq Study].

Whole-transcriptome analysis (RNA-seq) has been used to analyze changes in the expression of dopaminergic genes that encode proteins involved in the synthesis, inactivation, and neurotransmission of dopamine in the striatum, ventral tegmental area, raphe nuclei of the midbrain, hypothalamus, and hippocampus of male mice subjected to chronic social defeat. The expression of Th, Ddc, and Slc6A3 (Dat1) was upregulated, while that of Ppp1r1b and Sncg was downregulated in the ventral tegmental area; the expression of Th, Ddc, Drd2, and Sncg was downregulated in the raphe nuclei of midbrain; the expression of Th, Aldh2, and Ppp1r1b was upregulated, while that of Маоа was downregulated in the hypothalamus; Drd1 and Snca expression was downregulated and that of Sncb was upregulated in the striatum, and Sncb expression was upregulated in the hippocampus. There were no statistically significant changes in the expression of Comt, Maob, Drd3, Drd4, or Drd5 in the brain areas analyzed in stressed male mice (compared to control animals). Thus, the number of differentially expressed dopaminergic genes and the direction of expression changes in male mice experiencing chronic stress are specific to regions of the brain.

[Anxiogenic and anxiolytic effects of lithium chloride under preventive and therapeutic treatments of male mice with repeated experience of aggression].

Repeated experience of aggression in daily agonistic interactions is accompanied by development of changes in behaviors and psychoemotional states indicating the development of the psychopathology of aggressive behavior, which are difficult to correct by drugs used for decrease of aggression in the clinics. In this paper the influence of lithium chloride on the behavior of aggressive males in different tests assessing anxiety, communication and exploratory activity (elevated plus maze test, social interaction test, partition test), as well as aggressiveness (agonistic interaction test) were studied. Lithium chloride (Sigma-Aldrich Co, 100 mg/kg/day, i.p.) was administered preventively to male in ranging from the 7th day of agonistic interactions, as well as therapeutically to males with 21 days of aggression experience during the period without agonistic interactions. Also the effects of chronic lithium chloride treatment on behaviors of animals without agonistic interactions (intact mice) were studied. Period of drug and saline (as the controls) treatment--14 days. It has been shown that preventive lithium chloride treatment of male mice with repeated experience of aggression induced pronounced anxiogenic effect, under therapeutic treatment--nxiolytic effects. Anxiolytic effect was also observed in intact males. There is no effect of lithium chloride on aggression. Differences in the effects of lithium chloride under preveitive and therapeutic treatments, as well as the causes of individual sensitivity to the drug in male mice in one group were discussed.

[Pro-aggressive effect of diazepam in male mice with repeated experience of aggression].

Previous studies have reported that repeated experience of aggression is attended with the development of increased anxiety in male mice. The paper aimed to investigate effect of anxiolytic, diazepam, on the level of anxiety and aggression in these animals. The drug was chronically administrated for two weeks at the process of aggression experience acquisition. It was shown that diazepam decreased anxiety but didn't influence aggression level assessed by total time of attacks. However, diazepam decreased demonstration of aggressive grooming in part of aggressive males. Group of diazepam-treated aggressive males which displayed aggressive grooming didn't differ in level of anxiety and aggression in saline-treated male mice. Diazepam had anxiolytic and pro-aggressive effects in male mice without demonstrating aggressive grooming. Thus, we can conclude that anxiolytic effect of diazepam is accompanied with increased aggression as side effect in some male mice which have repeated experience of aggression.

[Effects of diazepam on mixed anxiety/depression state in male mice].

Chronic social defeat stress in daily agonistic interactions leads to the development of mixed anxiety/depression state in male mice. This paper aimed to study the effects of chronic diazepam treatment on the psychoemotional state of these animals. Diazepam (0.5 mg/kg, i/p, Polfa Tarchomin S. A.) or saline was chronically injected into male mice for two weeks on the background of continuing agonistic interactions (preventive treatment) or into male mice with mixed anxiety/depression state after stopping of social confrontations (therapeutic treatment). Then, the animals were studied in the partition, plus-maze and Porsolt' tests, estimating the levels of communicativeness, anxiety and depressiveness, respectively. Preventive diazepam treatment had a weak protective anxiolytic and pro-depressive effect. The therapeutic diazepam treatment didn't influence on the anxiety and depression-like state. Chronic diazepam was ineffective for the treatment of the mixed anxiety/depression state in male mice. Different effects ofdiazepam on anxiety and depression-like states under preventive treatment confirmed our conclusion shown earlier about the independent development of these pathologies at least in our experimental paradigm.

[Attenuating effect of sucrose solution intake on increase in aggression produced by fighting deprivation in male mice with repeated experience of victories].

It was found earlier that winners (male mice with experience 20 daily victories in aggressive agonistic encounters) showed enhanced aggression after a 2-week no-fight period, compared to their respective levels of aggressive behavior before the fighting deprivation. In this work we showed that sucrose solution intake in the deprivation period attenuated the level of post-deprivation aggression and decreased anxiety in such animals. Negative correlations were found between sucrose intake and aggression level. Putative mechanisms of attenuating sucrose effect on aggressive behavior are discussed.

Cell cycle arrest in the thymus and spleen in male mice under conditions of chronic social defeat stress: effects of diazepam.

The effects of chronic social defeat stress on the percentage of cells in different phases of the cell cycle and in apoptosis in the thymus and spleen of male mice were studied by the method of flow cytofluorometry. In stressed males, thymus weight decreased, the percent of proliferating thymocytes was significantly lower, and the percentage of G0-G1 cells was higher than in intact males. Stress substantially reduced the percentage of splenocytes in the G0-G1 phase and apoptotic cells, but the percentage of S and G2-M cells and proliferation index significantly increased. Chronic administration of anxiolytic diazepam prevented the majority of the changes in the percentage of cells in different phases of the cell cycle, but apoptosis in the thymus increased under these conditions. Possible association between cell cycle disorders, impairment of cell immunity, and chronic anxiety developing under conditions of long-term social defeat stress is considered.

[Effect of sodium valproate on aggressive behavior of male mice with various aggression experience].

Sector of Social Behavior Neurogenetics, Institute of Cytology and Genetics, Siberian Branch, Effects of sodium valproate on the aggressive behavior of male mice with 2- and 20-day positive fighting experience have been studied. It is established that valproate administered in a singe dose of 100 mg/kg has no effect on the behavior of male mice with a 2-day experience of aggression. The treatment of mice with 300 mg/kg of valproate significantly decreased the level of aggressive motivation and the percentage of animals demonstrating attacks and threats. In male mice with a 20-day experience of aggression, valproate decreased the time of hostile behavior in a dose-dependent manner. Valproate in a single dose of 300 mg/kg significantly decreased the level of aggressive motivation, but also produced a toxic effect, whereby 73% of aggressive males demonstrated long-term immobility and 45% exhibited movement abnormalities (falls) upon the treatment. It is suggested that changes in the brain neurochemical activity, which are caused by a prolonged experience of aggression, modify the effects of sodium valproate.

Limiting effect of diazepam on Lewis Lung carcinoma metastasis in anxious male mice.

AIM: It has been shown previously that chronic social defeat stress produces development of strong anxiety and increases intensity of experimental metastasis in the losers in comparison with the winners and control mice. The question was: is it possible to decrease the number of metastases in the losers by chronic or acute diazepam treatment. MATERIALS AND METHODS: Sensory contact model was used for generating male mice with repeated experience of social victories or defeats in daily agonistic interactions. Tumor cells of Lewis Lung Carcinoma (LLC) were injected into the tail vein of animals after 10 days of agonistic interactions. Then mice were treated acutely or chronically (7 days) with diazepam (1 mg/kg, i. p). Number of metastases in the lung was calculated in 16 days after tumor cell transplantation. RESULTS: Diazepam decreased the number of LLC metastases in anxious losers, whereas in the winners and control mice, without anxiety state, diazepam was ineffective. CONCLUSION: Well-known anxiolytic diazepam may decrease intensity of metastasis in anxious mice.