Mechanotransductive Receptor Piezo1 as a Promising Target in the Treatment of Neurological Diseases.

In recent years, increasing attention has been paid to the role of physical factors in biological processes. This direction was ultimately confirmed by the recent 2021 Nobel Prize in medicine and physiology awarded in ½ to Ardem Patapoutian for his discovery of Piezo1 and Piezo2 mechanosensitive receptors. Among them, Piezo2 is responsible for sensing touch, while Piezo1 is engaged in a variety of mechanotransduction events. Piezo1 is expressed in various central nervous system cells, while its expression may be affected in the course of various pathological conditions. Recently, thanks to the development of Piezo1 modulators (i.e. Yoda1, Jedi1/2 and Dooku2), it is possible to study the role of Piezo1 in the pathogenesis of various neurological diseases including ischemia, glioma, and age-related dementias. The results obtained in this field suggest that proper modulation of Piezo1 receptor might be beneficial in the course of various neurological diseases.

Antioxidant and Neuroprotective Activity of Vitamin E Homologues: In Vitro Study.

Here we present comparative data on the inhibition of lipid peroxidation by a variety of tocochromanols in liposomes. We also show for the first time the potential neuroprotective role of all the vitamin E homologues investigated on the neuronally differentiated human neuroblastoma SH-SY5Y cell line. α-Tocopherol had nearly no effect in the inhibition of lipid peroxidation, while ß-, γ-, and δ-tocopherols inhibited the reaction completely when it was initiated in a lipid phase. Similar effects were observed for tocotrienol homologues. Moreover, in this respect plastochromanol-8 was as effective as ß-, γ-, and δ-tocochromanols. When the prenyllipids were investigated in a 1,1-diphenyl-2-picrylhydrazyl (DPPH) test and incorporated into different lipid carriers, the radical oxidation was most pronounced in liposomes, followed by mixed micelles and the micellar system. When the reaction of tocochromanols was examined in niosomes, the oxidation was most pronounced for α-tocopherol and plastochromanol-8, followed by α-tocotrienol. Next, using retinoic acid-differentiated SH-SY5Y cells, we tested the protective effects of the compounds investigated on hydrogen peroxide (H2O2)-induced cell damage. We showed that tocotrienols were more active than tocopherols in the oxidative stress model. Plastochromanol-8 had a strong inhibitory effect on H2O2-induced lactate dehydrogenase (LDH) release and H2O2-induced decrease in cell viability. The water-soluble α-tocopherol phosphate had neuroprotective effects at all the concentrations analyzed. The results clearly indicate that structural differences between vitamin E homologues reflect their different biological activity and indicate their potential application in pharmacological treatments for neurodegenerative diseases. In this respect, the application of optimal tocochromanol-carrying structures might be critical.

Stiffening of DU145 prostate cancer cells driven by actin filaments - microtubule crosstalk conferring resistance to microtubule-targeting drugs.

The crucial role of microtubules in the mitotic-related segregation of chromosomes makes them an excellent target for anticancer microtubule targeting drugs (MTDs) such as vinflunine (VFL), colchicine (COL), and docetaxel (DTX). MTDs affect mitosis by directly perturbing the structural organisation of microtubules. By a direct assessment of the biomechanical properties of prostate cancer DU145 cells exposed to different MTDs using atomic force microscopy, we show that cell stiffening is a response to the application of all the studied MTDs (VFL, COL, DTX). Changes in cellular rigidity are typically attributed to remodelling of the actin filaments in the cytoskeleton. Here, we demonstrate that cell stiffening can be driven by crosstalk between actin filaments and microtubules in MTD-treated cells. Our findings improve the interpretation of biomechanical data obtained for living cells in studies of various physiological and pathological processes.

Maternal Immune Activation Sensitizes Male Offspring Rats to Lipopolysaccharide-Induced Microglial Deficits Involving the Dysfunction of CD200-CD200R and CX3CL1-CX3CR1 Systems.

Early life challenges resulting from maternal immune activation (MIA) may exert persistent effects on the offspring, including the development of psychiatric disorders, such as schizophrenia. Recent evidence has suggested that the adverse effects of MIA may be mediated by neuron-microglia crosstalk, particularly CX3CL1-CX3CR1 and CD200-CD200R dyads. Therefore, the present study assessed the behavioural parameters resembling schizophrenia-like symptoms in the adult male offspring of Sprague-Dawley rats that were exposed to MIA and to an additional acute lipopolysaccharide (LPS) challenge in adulthood, according to the "two-hit" hypothesis of schizophrenia. Simultaneously, we aimed to clarify the role of the CX3CL1-CX3CR1 and CD200-CD200R axes and microglial reactivity in the brains of adult offspring subjected to MIA and the "second hit" wit LPS. In the present study, MIA generated a range of behavioural changes in the adult male offspring, including increased exploratory activity and anxiety-like behaviours. The most intriguing finding was observed in the prepulse inhibition (PPI) test, where the deficit in the sensorimotor gating was age-dependent and present only in part of the rats. We were able to distinguish the occurrence of two groups: responsive and non-responsive (without the deficit). Concurrently, based on the results of the biochemical studies, MIA disrupted mainly the CD200-CD200R system, while the changes of the CX3CL1-CX3CR1 axis were less evident in the frontal cortex of adult non-responsive offspring. MIA markedly affected the immune regulators of the CD200-CD200R pathway as we observed an increase in cortical IL-6 release in the responsive group and IL-4 in the non-responsive offspring. Importantly, the "second hit" generated disturbances at the behavioural and biochemical levels mostly in the non-responsive adult animals. Those offspring were characterized both by disturbed PPI and "priming" microglia. Altogether, the exposure to MIA altered the immunomodulatory mechanisms, including the CD200-CD200R axis, in the brain and sensitized animals to subsequent immunological challenges, leading to the manifestation of schizophrenia-like alterations.

Targeting the NLRP3 Inflammasome-Related Pathways via Tianeptine Treatment-Suppressed Microglia Polarization to the M1 Phenotype in Lipopolysaccharide-Stimulated Cultures.

An increasing body of evidence postulates that microglia are the main mediators of inflammation-related disorders, including depression. Since activated microglia produce a wide range of pro- and anti-inflammatory factors, the modulation of M1/M2 microglial polarization by antidepressants may be crucial in the treatment of depression. The current paper aimed to investigate the impact of tianeptine on the microglia's viability/death parameters, and on M1/M2 microglial activation in response to lipopolysaccharide (LPS) stimulation. Furthermore, the molecular mechanisms via which tianeptine affected the LPS-evoked changes were investigated. The results revealed that tianeptine had partially protective effects on the changes in microglia viability/death evoked by LPS. Tianeptine attenuated microglia activation by decreasing the expression of cluster of differentiation 40 (CD40), and major histocompatibility complex class II (MHC II) markers, as well as the release of pro-inflammatory factors: interleukin (IL)-1ß, IL-18, IL-6, tumor necrosis factor alpha (TNF-α), and chemokine CC motif ligand 2 (CCL2), and the production of nitric oxide and reactive oxygen species. In contrast, we did not observe an impact of tianeptine on M2 microglia measured by IL-4, IL-10, TGF-ß, and insulin-like growth factor 1 (IGF-1) expression. Moreover, we demonstrated an inhibitory effect of tianeptine on the LPS-induced activation of the nucleotide-binding oligomerization domain-like (NOD-like) receptor pyrin-containing 3 inflammasome (NLRP3) inflammasome subunits, NLRP3 and caspase-1, as well as the ability of tianeptine to reduce Toll-like receptor 4 (TLR4) levels, as well as the phosphorylation of extracellular signal-related kinases 1 and 2 (ERK1/2) and of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Collectively, we demonstrated that tianeptine has protective properties and inhibits M1 polarization, thus attenuating the production of inflammatory mediators. Moreover, we found that M1 microglia suppression may be related to the NLRP3 inflammasome and TLR4 signaling. These findings suggest that a better understanding of the multifaceted mechanisms of tianeptine action on microglia may increase the effectiveness of therapy, where inflammation is a central hallmark.

Stimulatory effect of desipramine on lung metastases of adenocarcinoma MADB 106 in stress highly-sensitive and stress non-reactive rats.

The effect of antidepressant drugs on tumor progress is very poorly recognized. The aim of the present study was to examine the effect of individual reactivity to stress and 24-day desipramine (DES) administration on the metastatic colonization of adenocarcinoma MADB 106 cells in the lungs of Wistar rats. Wistar rats were subjected to stress procedure according to the chronic mild stress (CMS) model of depression for two weeks and stress highly-sensitive (SHS) and stress non-reactive (SNR) rats were selected. SHS rats were more prone to cancer metastasis than SNR ones and chronic DES treatment further increased the number of lung metastases by 59% and 50% in comparison to vehicle-treated appropriate control rats. The increase in lung metastases was connected with DES-induced skew macrophage activity towards M2 functional phenotype in SHS and SNR rats. Moreover, during 24h after DES injection in healthy rats, the decreased number of TCD8+ and B cells in SHS and SNR rats as well as NK cell cytotoxic activity in SNR rats could be attributed to the lowered capacity to defend against cancer metastasis observed in chronic DES treated and tumor injected rats.

Prenatal stress affects viability, activation, and chemokine signaling in astroglial cultures.

CXCL12/SDF-1α and CX3CL1/fractalkine are constitutively expressed in the brain, which indicates their significant functions. Emerging evidence highlights the role of astrocytes and the immune system in the pathophysiology of stress-related disorders. The aim of this study was to assess whether prenatal stress affects chemokine signaling, cell viability/activation, and the iNOS pathway in astroglial cultures. Our results showed that prenatal stress lowered astrocyte viability and simultaneously increased GFAP expression. Furthermore, CX3CL1 production and the CXCL12/CXCR4-7 axis were also altered by prenatal stress. Taken together, malfunctions caused by prenatal stress may adversely influence brain development, leading to long-term effects on adult brain function and behavior.

Evaluation of the effectiveness of chronic antidepressant drug treatments in the hippocampal mitochondria - A proteomic study in an animal model of depression.

Several lines of evidence indicate that adverse experience in early life may be a triggering factor for disturbances in the brain mitochondrial proteins and lead to the development of depression in adulthood. On the other hand, little is known about the impact of chronic administration of various antidepressant drugs on the brain mitochondria, as a target for the pharmacotherapy of depression. The purpose of our study was to compare the impact of chronic treatment with two antidepressant drugs with different mechanisms of action, a tricyclic antidepressant (TCA), imipramine, and an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class, fluoxetine, on the mitochondria-enriched subproteome profile in the hippocampus of 3-month-old male rats following a prenatal stress procedure (an animal model of depression). We clearly confirmed that chronic imipramine and fluoxetine administration not only normalized depression-like disturbances evoked by the prenatal stress procedure but also modulated the mitochondria-enriched subproteome profile in the hippocampus of adult offspring rats. In line with this, two-dimensional electrophoresis coupled with mass spectrometry showed a statistically significant down-regulation of 14-3-3 and cytochrome bc1 proteins and an up-regulation of COP9 signalosome expression after chronic imipramine treatment in the hippocampus of prenatally stressed offspring. Fluoxetine administration strongly up-regulated the expression of cathepsin D, one of the key proteins involved in the prevention of the development of neurodegenerative processes. Furthermore, this antidepressant treatment enhanced expression of proteins engaged in the improvement of learning and memory processes (STMN1, Dnm-1) as well as in mitochondrial biogenesis and defense against oxidative stress (DJ-1). These findings provide new evidence that chronic administration of antidepressants exerts a varied impact on the mitochondria-enriched subproteome in the hippocampus of adult rats following a prenatal stress procedure. In particular, the effect of fluoxetine requires additional experiments to elucidate the possible beneficial biological consequences underlying the effects mediated by this antidepressant.

Fractalkine Attenuates Microglial Cell Activation Induced by Prenatal Stress.

The potential contribution of inflammation to the development of neuropsychiatric diseases has recently received substantial attention. In the brain, the main immune cells are the microglia. As they are the main source of inflammatory factors, it is plausible that the regulation of their activation may be a potential therapeutic target. Fractalkine (CX3CL1) and its receptor CX3CR1 play a crucial role in the control of the biological activity of the microglia. In the present study, using microglial cultures we investigated whether fractalkine is able to reverse changes in microglia caused by a prenatal stress procedure. Our study found that the microglia do not express fractalkine. Prenatal stress decreases the expression of the fractalkine receptor, which in turn is enhanced by the administration of exogenous fractalkine. Moreover, treatment with fractalkine diminishes the prenatal stress-induced overproduction of proinflammatory factors such as IL-1ß, IL-18, IL-6, TNF-α, CCL2, or NO in the microglial cells derived from prenatally stressed newborns. In conclusion, the present results revealed that the pathological activation of microglia in prenatally stressed newborns may be attenuated by fractalkine administration. Therefore, understanding of the role of the CX3CL1-CX3CR1 system may help to elucidate the mechanisms underlying the neuron-microglia interaction and its role in pathological conditions in the brain.

The Effect of Chronic Mild Stress and Imipramine on the Markers of Oxidative Stress and Antioxidant System in Rat Liver.

Liver abnormalities have been reported to occur in up to 20 % of patients on a long-term therapy with the tricyclic antidepressant drug imipramine (IMI). The mechanism involved in this IMI-induced process is unknown but a contribution of oxidative stress is highly likely. Chronic mild stress (CMS) is widely used for modeling depressive-like behavior in rats. In the present study, we examined the effects of CMS and chronic IMI treatment, applied alone or in combination, on the levels of oxidative stress markers, such as reactive oxygen species (ROS), malondialdehyde (MDA), non-protein sulfhydryl groups, and sulfane sulfur as well as on activities of key antioxidant enzymes: catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase in the rat liver. Administration of IMI for 5 weeks to rats subjected to CMS resulted in a gradual significant reduction of anhedonia measured by sucrose intake, in a majority of animals (CMS IMI-reactive, CMS IMI-R), although about 20 % of rats did not respond to the IMI treatment (CMS IMI non-reactive, CMS IMI-NR). CMS-induced hepatic oxidative stress, estimated by increased ROS and MDA concentrations, was not prevented by the IMI administration, moreover, in CMS IMI-NR animals, the level of the marker of lipid peroxidation, i.e., MDA was increased in comparison to CMS-subjected rats and activity of antioxidant enzymes (GPx and CAT) was decreased compared to IMI-treated rats. The clinical significance of this observation remains to be established.

Anti-inflammatory properties of tianeptine on lipopolysaccharide-induced changes in microglial cells involve toll-like receptor-related pathways.

Accumulating evidence suggests that activation of microglia plays a key role in the pathogenesis of depression. Activated microglia produce a wide range of factors whose prolonged or excessive release may lead to brain disorders. Thus, the inhibition of microglial cells may be beneficial in the treatment of depressive diseases. Tianeptine is an atypical antidepressant drug with proven clinical efficacy, but its mechanism of action remains still not fully understood. In the present study, using microglial cultures we investigated whether tianeptine modifies microglial activation after lipopolysaccharide (LPS) stimulation and which intracellular pathways are involved in the activity of this antidepressant. Our study shows that tianeptine attenuated the LPS-evoked inflammatory activation of microglia by decreasing the expression of proinflammatory cytokines such as IL-1ß, IL-18, IL-6 and tumor necrosis factor α (TNF-α), the release of nitric oxide (NO) and reactive oxygen species (ROS) as well as the expression of inducible nitric oxide synthase. Analyses of signaling pathways demonstrate that tianeptine led to the suppression of LPS-induced TLR4 expression and ERK1/2 phosphorylation. Furthermore, our study reveals the inhibitory impact of tianeptine on caspase-3-induced PKCδ degradation and consequently on the activation of NF-κB factor in microglial cells. Taken together, present results show anti-inflammatory properties of tianeptine in microglial cultures stimulated by LPS. This study provides evidence that the inhibition of microglial activation may underlie the therapeutic activity of tianeptine. Our findings show the anti-inflammatory effect of tianeptine (TIA) in lipopolisaccharide (LPS)-stimulated microglial cells. The beneficial tianeptine action is mediated through the inhibition of Toll-like receptor 4 (TLR4) expression as well as the TLR4-related pathways: extracellular signal-regulated kinase 1/2 (ERK1/2), caspase-3-dependent protein kinase δ (PKCδ) cleavage and the expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). These findings may provide a new therapeutic strategy for treatment of disorders based on neuroinflammation, including depression.

Mitochondrial aldehyde dehydrogenase activation by Alda-1 inhibits atherosclerosis and attenuates hepatic steatosis in apolipoprotein E-knockout mice.

BACKGROUND: Mitochondrial dysfunction has been shown to play an important role in the development of atherosclerosis and nonalcoholic fatty liver disease (NAFLD). Mitochondrial aldehyde dehydrogenase (ALDH2), an enzyme responsible for the detoxification of reactive aldehydes, is considered to exert protective function in mitochondria. We investigated the influence of Alda-1, an activator of ALDH2, on atherogenesis and on the liver steatosis in apolipoprotein E knockout (apoE(-/-)) mice. METHODS AND RESULTS: Alda-1 caused decrease of atherosclerotic lesions approximately 25% as estimated by "en face" and "cross-section" methods without influence on plasma lipid profile, atherosclerosis-related markers of inflammation, and macrophage and smooth muscle content in the plaques. Plaque nitrotyrosine was not changed upon Alda-1 treatment, and there were no changes in aortic mRNA levels of factors involved in antioxidative defense, regulation of apoptosis, mitogenesis, and autophagy. Hematoxylin/eosin staining showed decrease of steatotic changes in liver of Alda-1-treated apoE(-/-) mice. Alda-1 attenuated formation of 4-hydroxy-2-nonenal (4-HNE) protein adducts and decreased triglyceride content in liver tissue. Two-dimensional electrophoresis coupled with mass spectrometry identified 20 differentially expressed mitochondrial proteins upon Alda-1 treatment in liver of apoE(-/-) mice, mostly proteins related to metabolism and oxidative stress. The most up-regulated were the proteins that participated in beta oxidation of fatty acids. CONCLUSIONS: Collectively, Alda-1 inhibited atherosclerosis and attenuated NAFLD in apoE(-/-) mice. The pattern of changes suggests a beneficial effect of Alda-1 in NAFLD; however, the exact liver functional consequences of the revealed alterations as well as the mechanism(s) of antiatherosclerotic Alda-1 action require further investigation.

Prenatal stress affects insulin-like growth factor-1 (IGF-1) level and IGF-1 receptor phosphorylation in the brain of adult rats.

It has been shown that stressful events occurring in early life have a powerful influence on the development of the central nervous system. Insulin-like growth factor-1 (IGF-1) promotes the growth, differentiation and survival of both neurons and glial cells and is thought to exert antidepressant-like activity. Thus, it is possible that disturbances in the function of the IGF-1 system may be responsible for disturbances observed over the course of depression. Prenatal stress was used as a valid model of depression. Adult male offspring of control and stressed rat dams were subjected to behavioural testing (forced swim test). The level of IGF-1 in the blood and the expression of IGF-1, IGF-1R, and IRS-1/2 in the hippocampus and frontal cortex using RT-PCR, ELISA and western blotting were measured. In addition the effect of intracerebroventricularly administered IGF-1 and/or the IGF-1R receptor antagonist JB1 in the forced swim test was studied. Prenatally stressed rats showed depressive like behaviour, including increased immobility time as well as decreased mobility and climbing. Intracerebroventricular administration of IGF-1 reversed these effects in stressed animals, whereas concomitant administration of the IGF-1R antagonist JB1 completely blocked the effects. Biochemical analysis of homogenates from the hippocampus and frontal cortex revealed decreases in IGF-1 level and IGF-1R phosphorylation along with disturbances in IRS-1 phosphorylation. These findings reveal that prenatal stress alters IGF-1 signalling, which may contribute to the behavioural changes observed in depression.

Inhibitory effect of antidepressants on B16F10 melanoma tumor growth.

BACKGROUND: Antidepressant drugs, like fluoxetine, a selective serotonin reuptake inhibitor, desipramine, a nonselective noradrenaline reuptake inhibitor, and mirtazapine, an antagonist of noradrenaline α2 auto- and heteroreceptors, are widely used for the treatment of depressive symptoms in cancer patients. Since these antidepressants have different activities targeting the immune system, they might also modulate tumor growth in cancer patients. METHODS: In the present study, we investigated the effects of administration of antidepressant drugs: fluoxetine, desipramine and mirtazapine on B16F10 melanoma tumor growth. These drugs were administered intraperitoneally (ip) for 17 days after subcutaneous injection of B16F10 melanoma cells to male C57BL/6J mice. RESULTS: Fluoxetine significantly inhibited melanoma solid tumor growth and desipramine tended to decrease this parameter whereas mirtazapine had no effect. CONCLUSION: The inhibitory effect of fluoxetine on melanoma growth was associated with an increased mitogen-induced T cell proliferation which may at least partly participate in the mechanism of the antitumor effect of this antidepressant. It appears that the inhibitory effect of fluoxetine on tumor growth is not related with changes in cytokine levels except for IL-10.

Inhibition of 2,4-dinitrofluorobenzene-induced contact hypersensitivity reaction by antidepressant drugs.

BACKGROUND: Contact hypersensitivity (CHS) induced by a topical application of hapten - 2,4-dinitrofluorobenzene (DNFB), is a T cytotoxic (Tc)1-cell-mediated antigen-specific type of skin inflammation. Recently, it has been shown that antidepressant drugs inhibit the T helper (Th)1-mediated CHS reaction induced by picryl chloride. The aim of present study was to establish the effect of two-week desipramine or fluoxetine administration on the CHS reaction induced by DNFB. METHODS: Balb/c (H-2(d)) male mice were divided into six groups: 1) vehicle-treated negative control group; 2) desipramine-treated negative control group; 3) fluoxetine-treated negative control group; 4) vehicle-treated DNFB group (positive control group); 5) desipramine-treated DNFB group; 6) fluoxetine-treated DNFB group. T lymphocytes proliferation was determined by incorporation of [(3)H]-thymidine to DNA of concanavalin A stimulated cells. ELISA test was used for estimation of cytokines production. RESULTS: The antidepressants significantly suppressed the CHS reaction mediated by Tc1 cells: desipramine by 55% and fluoxetine by 54% compared to the positive control. Moreover, the antidepressants decreased the proliferative activity of splenocytes and the ability of splenocytes to produce interleukin (IL)-6 and interferon (IFN)-γ and increased IL-10 production by the lymph node (LN) cells of DNFB-treated mice. CONCLUSION: The results of the present study show that the Tc1-dependent reactivity to DNFB is significantly suppressed by antidepressant drugs, which suggests their inhibitory effect on Tc1 mediated immunity.

Inhibitory effect of antidepressant drugs on contact hypersensitivity reaction.

BACKGROUND: Contact hypersensitivity (CS) reaction in the skin is T-cell mediated immune reaction which plays a major role in the pathogenesis and chronicity of various inflammatory skin disorders and, like other delayed-type hypersensitivity (DTH) reactions, affords immunity against tumor cells and microbes. CS response is a self-limiting reaction, and interleukin (IL)-10 is considered to be a natural suppressant of cutaneous inflammatory response. Recently, it has been demonstrated that major depression is related to activation of the inflammatory response and elevation of some parameters of cell-mediated immunity. It has been suggested that such activation of the immune system may play a role in etiology of depression. If this immunoactivation is involved in etiology of depression, one would expect that antidepressant agents may have negative immunoregulatory effects. To the best of our knowledge, the effect of antidepressants on contact hypersensitivity has not been studied. METHODS: The aim of the present study was to establish the effect of prolonged desipramine or fluoxetine treatment on CS reaction to picryl chloride. RESULTS: Antidepressants significantly suppressed CS reaction, fluoxetine by 53% whereas desipramine by 47% compared to positive control. Moreover, desipramine and fluoxetine decreased relative weight of auxillary lymph nodes. Desipramine decreased also relative weight of inguinal lymph nodes and spleens whereas desipramine and fluoxetine increased production of IL-10 in comparison to positive control. CONCLUSION: The observed effect of antidepressant drugs on CS reaction is consistent with the hypothesis that T-cell mediated immunity is targeted by antidepressants.

Stimulatory effect of antidepressant drug pretreatment on progression of B16F10 melanoma in high-active male and female C57BL/6J mice.

The effect of a two-week desipramine or fluoxetine (10 mg/kg, i.p.) pretreatment on B16F10 melanoma growth in 3-5 month old female and male C57BL/6J mice differing in behavioral characteristics (high- vs. low-active) was compared. Antidepressant pretreatment increased metastasis formation, shortened the survival, decreased splenocyte anti-tumor natural killer cell cytotoxicity (in vitro), and the pro-inflammatory cytokine IL-12p40, IFN-γ production while it increased anti-inflammatory cytokine IL-10 production in high-active males (desipramine) or females (fluoxetine). The obtained results emphasize a stimulatory effect of pretreatment with antidepressants on progress of B16F10 melanoma that depends on gender and behavioral characteristics of the animal.

Effects of neurosteroids on the human corticotropin-releasing hormone gene.

Increased activity of hypothalamic-pituitary-adrenal (HPA) axis and hypersecretion of corticotropin-releasing hormone (CRH) are known to be important factors in pathogenesis of some stress-related diseases. Some neurosteroids exert anxiolytic and antidepressant effects probably by inhibition of HPA axis activity. The aim of our study was to find out if neurosteroids can directly affect human CRH gene transcription. The effect of allopregnanolone (ALLO), allotetrahydrodeoxycorticosterone (THDOC), pregnenolone (PGL), PGL sulfate (PGL-S), dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEA-S) on CRH expression was determined in differentiated Neuro-2A cells stably transfected with plasmid containing a fragment of human CRH promoter (-663 to + 124 bp) linked to the chloramphenicol acetyltransferase (CAT) reporter gene. It was found that PGL (0.3-30 µM), ALLO (1-30 µM) and THDOC (1-30 µM) present in the culture medium for 5 days in the concentration-dependent manner inhibited CRH-CAT activity. These neurosteroids also inhibited forskolin-stimulated CRH gene transcription with similar potency. In contrast, PGL-S, DHEA and DHEA-S in a concentration from 0.01 to 10 µM had no effect on basal and forskolin-stimulated CRH activity. Further experiments revealed that wortmannin (an inhibitor of phosphatidylinositol 3-kinase; PI3-K) at concentrations of 0.01 and 0.02 µM did not change the inhibitory effect of ALLO (3 µM) and PGL (1 µM) on CRH gene transcription. Moreover, ALLO (3 µM) and PGL (1 µM) present in the culture medium for 5 days did not change the amount of active, phosphorylated form of protein kinase B (PKB, Akt) and extracellular signal-regulated kinase (ERK). The obtained results indicate that PGL, ALLO and THDOC inhibited basal and forskolin-induced CRH gene promoter activity in the differentiated Neuro-2A cells and that these effects did not depend on the activation of PI3-K/Akt and ERK-MAPK pathways.

Effects of ethylene glycol ethers on cell viability in the human neuroblastoma SH-SY5Y cell line.

Ethylene glycol ethers (EGEs) are a class of chemicals used extensively in the manufacture of a wide range of domestic and industrial products, which may result in human exposure and toxicity. Hematologic and reproductive toxicity of EGEs are well known whereas their action on neuronal cell viability has not been studied so far. In the present study, we investigated the effects of some EGEs on cell viability and on the hydrogen peroxide-induced damage in the human neuroblastoma (SH-SY5Y) cells. It has been found that 2-phenoxyethanol in a concentration-dependent manner (5-25 mM, 24 h) increased the basal and H(2)O(2)-induced lactate dehydrogenase (LDH) release and 3-[4,5-dimethylthiazol-2-yl]2,5-diphenyl tetrazolium bromide (MTT) reduction. 2-Butoxyethanol given alone did not affect LDH release and MTT reduction but concentration-dependently enhanced the cytotoxic effect of H(2)O(2). 2-Isopropoxyethanol significantly and concentration-dependently (1-25 mM) increased the basal LDH release and attenuated MTT reduction, but did not potentiate the cytotoxic effect of H(2)O(2). Contrary to this, 2-methoxyethanol did not show a cytotoxic effect while 2-ethoxyethanol at high concentrations intensified the hydrogen peroxide action. This study demonstrated that among the EGEs studied, 2-phenoxyethanol showed the most consistent cytotoxic effect on neurons in in vitro conditions and enhanced the hydrogen peroxide action. 2-Isopropoxyethanol had also a potent cytotoxic effect, but it did not enhance the hydrogen peroxide action, whereas 2-butoxyethanol only potentiated cytotoxic effect of H(2)O(2). It is concluded that the results of the present study should be confirmed in in vivo conditions and that some EGEs, especially 2-phenoxyethanol, 2-butoxyethanol and 2-isopropoxyethanol, may be responsible for initiation or exacerbation of neuronal cell damage.

[Immunological and endocrinological pattern in ADHD etiopathogenesis]. / Udzial czynników immunologicznych i endokrynnych w etiopatogenezie ADHD.

Attention-Deficit Hyperactivity Disorder (ADHD) is the most prevalent neurodevelopmental disorder among children. There are 3 subtypes of ADHD: (1) with prevalent inattentive symptoms (2) with prevalent hyperactive-impulsive symptoms and (3) the combined subtype. It typically manifests itself before age 7 years and occurs more frequently in boys than in girls. It is diagnosed when the hyperactivity, impulsiveness and inattention last long, appear at least in two environments and their intensity impairs the functioning of the child. The etiology of ADHD is not well-known but recent studies have shown that genetic factors are of big importance. Also several environmental influences that raise the risk for ADHD development have been identified. Recently, it has been postulated that the reduced activity of the dopaminergic and noradrenergic systems play a crucial role in ADHD pathogenesis. It is evidenced by the fact that drugs intensifying the noradrenergic and dopaminergic transmission are the most successful for ADHD treatment. At present, it has been also postulated that the disturbances in endocrine and immune systems are involved in the ADHD pathogenesis. Interconnections between functions of these systems and function of neurotransmitters are better recognized now and show that disturbances in their cooperation can be involved in some psychiatric disorders. In the case of ADHD, most data are related to disturbances in the activity of the hypothalamus-pituitary-adrenal (HPA) axis activity. In particular, the lower level of cortisol in children with ADHD, especially in the hyperactive-impulsive type ADHD, the disturbance in the circadian rhythm of this steroid and the lack of its inhibition by the dexamethasone have been documented. Many clinical data indicate that in children with ADHD, the psychological stress evokes a weaker activation of the HPA axis than in the control group. Epidemiological and preclinical investigations have shown that the disturbance in the HPA axis in ADHD can result from an excessive exposure to glucocorticoids in the fetal and early postnatal periods. Glucocorticoid administration in this period of life can provoke permanent changes in the level of brain glucocorticoid receptors and, in consequence, dysregulation of HPA axis activity, disturbances in biosynthesis of the neurotransmitters and their receptors and changes in the intracellular pathways. Glucocorticoids are known to intensify the dopaminergic system activity, so the decrease in their expression in ADHD can cause the hypofunction of this system. Since the attention and motor activity disorders often occur in children with generalized resistance to thyroid hormones, their role in ADHD pathogenesis was evaluated. However, most of the studies indicated that the levels of triiodothyronine (T3), thyroxine (T4), the free thyroxine, and the thyroid stimulating hormone (TSH) did not change in ADHD. Preclinical data concerning the role of androgens in the ADHD pathogenesis suggest that the elevated testosterone level can diminish the brain blood flow in the frontal cortex, via lowering of the level of estrogen receptor-alpha and the vascular endothelial growth factor (VEGF), and in consequence disturb processes of the memory. The association between ADHD and the polymorphism of the gene coding for androgen receptor, which leads to its higher expression has been found, however, the issue of the androgen participation in the ADHD pathogenesis is still poorly recognized. Frequent co-occurrence of ADHD and allergic diseases and correlation between ADHD and streptococcus-mediated neuropsychiatric disorders suggest the participation of the immune system in the ADHD pathogenesis. Also experimental data from an animal model of ADHD showed changes in the expression in at least several essential genes for the immune system function. However, on the other hand, the lack of the association between asthma and immunoglobulin E- dependent athopic reaction and the lack of the elevated anti-ganglia antibodies in ADHD speaks against the implication of autoimmunity in ADHD pathogenesis. Since psychostimulants, the most therapeutically efficient drugs in ADHD, not only increase the level of the dopamine and norepinephrines but also increase the activity of the HPA axis and reduce the concentration of androgens, it cannot be excluded that their beneficial effect can partly issue from a normalizing action on hormonal levels. However, currently available clinical and experimental data do not permit precise estimation of the role of endocrine and immune systems in the pathogenesis of ADHD and in therapeutic action of psychostimulants.